diff --git a/HISTORY.rst b/HISTORY.rst
index 89ee0785..33713b31 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -11,6 +11,9 @@ Release History
   (`issue #174 <https://github.com/platformio/platformio/issues/174>`_)
 * Added global ``-f, --force`` option which will force to accept any
   confirmation prompts (`issue #152 <https://github.com/platformio/platformio/issues/152>`_)
+* Allowed to add more boards to existing
+  `platformio.ini <http://docs.platformio.org/en/latest/projectconf.html>`__
+  (`issue #167 <https://github.com/platformio/platformio/issues/167>`_)
 * Allowed to choose which library to update
   (`issue #168 <https://github.com/platformio/platformio/issues/168>`_)
 * Disabled automatic updates by default for platforms, packages and libraries
diff --git a/platformio/commands/init.py b/platformio/commands/init.py
index 750e4a62..cd301978 100644
--- a/platformio/commands/init.py
+++ b/platformio/commands/init.py
@@ -31,17 +31,6 @@ def validate_boards(ctx, param, value):  # pylint: disable=W0613
 @click.option("--disable-auto-uploading", is_flag=True)
 def cli(project_dir, board, disable_auto_uploading):
 
-    project_file = join(project_dir, "platformio.ini")
-    src_dir = join(project_dir, "src")
-    lib_dir = join(project_dir, "lib")
-    if all([isfile(project_file), isdir(src_dir), isdir(lib_dir)]):
-        raise exception.ProjectInitialized()
-
-    builtin_boards = set(get_boards().keys())
-    if board and not set(board).issubset(builtin_boards):
-        raise exception.UnknownBoard(
-            ", ".join(set(board).difference(builtin_boards)))
-
     # ask about auto-uploading
     if board and app.get_setting("enable_prompts"):
         disable_auto_uploading = not click.confirm(
@@ -56,7 +45,7 @@ def cli(project_dir, board, disable_auto_uploading):
         click.secho("\nThe current working directory", fg="yellow", nl=False)
         click.secho(" %s " % project_dir, fg="cyan", nl=False)
         click.secho(
-            "will be used for the new project.\n"
+            "will be used for project.\n"
             "You can specify another project directory via\n"
             "`platformio init -d %PATH_TO_THE_PROJECT_DIR%` command.",
             fg="yellow"
@@ -72,49 +61,63 @@ def cli(project_dir, board, disable_auto_uploading):
     click.echo("%s - Put here project specific or 3-rd party libraries" %
                click.style("lib", fg="cyan"))
 
-    if (not app.get_setting("enable_prompts") or
-            click.confirm("Do you want to continue?")):
-
-        for d in (src_dir, lib_dir):
-            if not isdir(d):
-                makedirs(d)
-        if not isfile(project_file):
-            copyfile(join(get_source_dir(), "projectconftpl.ini"),
-                     project_file)
-            if board:
-                fill_project_envs(project_file, board, disable_auto_uploading)
-        click.secho(
-            "\nProject has been successfully initialized!\nUseful commands:\n"
-            "`platformio run` - process/build project from the current "
-            "directory\n"
-            "`platformio run --target upload` or `platformio run -t upload` "
-            "- upload firmware to embedded board\n"
-            "`platformio run --target clean` - clean project (remove compiled "
-            "files)",
-            fg="green"
-        )
-    else:
+    if (app.get_setting("enable_prompts") and
+            not click.confirm("Do you want to continue?")):
         raise exception.AbortedByUser()
 
+    project_file = join(project_dir, "platformio.ini")
+    src_dir = join(project_dir, "src")
+    lib_dir = join(project_dir, "lib")
+
+    for d in (src_dir, lib_dir):
+        if not isdir(d):
+            makedirs(d)
+
+    if not isfile(project_file):
+        copyfile(join(get_source_dir(), "projectconftpl.ini"),
+                 project_file)
+
+    if board:
+        fill_project_envs(project_file, board, disable_auto_uploading)
+
+    click.secho(
+        "\nProject has been successfully initialized!\nUseful commands:\n"
+        "`platformio run` - process/build project from the current "
+        "directory\n"
+        "`platformio run --target upload` or `platformio run -t upload` "
+        "- upload firmware to embedded board\n"
+        "`platformio run --target clean` - clean project (remove compiled "
+        "files)",
+        fg="green"
+    )
+
 
 def fill_project_envs(project_file, board_types, disable_auto_uploading):
     builtin_boards = get_boards()
     content = []
-    for type_ in board_types:
-        if type_ not in builtin_boards:
-            continue
-        else:
-            content.append("")
+    used_envs = []
 
+    with open(project_file) as f:
+        used_envs = [l.strip() for l in f.read().splitlines() if
+                     l.strip().startswith("[env:")]
+
+    for type_ in board_types:
         data = builtin_boards[type_]
+        env_name = "[env:autogen_%s]" % type_
+
+        if env_name in used_envs:
+            continue
+
+        content.append("")
+        content.append(env_name)
+        content.append("platform = %s" % data['platform'])
+
         # find default framework for board
         frameworks = data.get("frameworks")
-        content.append("[env:autogen_%s]" % type_)
-        content.append("platform = %s" % data['platform'])
         if frameworks:
             content.append("framework = %s" % frameworks[0])
-        content.append("board = %s" % type_)
 
+        content.append("board = %s" % type_)
         content.append("%stargets = upload" % ("# " if disable_auto_uploading
                                                else ""))
 
diff --git a/platformio/exception.py b/platformio/exception.py
index 451e7761..daaa176e 100644
--- a/platformio/exception.py
+++ b/platformio/exception.py
@@ -96,12 +96,6 @@ class UnsupportedArchiveType(PlatformioException):
     MESSAGE = "Can not unpack file '%s'"
 
 
-class ProjectInitialized(PlatformioException):
-
-    MESSAGE = ("Project is already initialized. "
-               "Process it with `platformio run` command")
-
-
 class ProjectEnvsNotAvailable(PlatformioException):
 
     MESSAGE = "Please setup environments in `platformio.ini` file."