diff --git a/CHANGELOG.md b/CHANGELOG.md
index e9facba4..2fef9af6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ CHANGELOG for FlatCAM beta
 
 - in the 'cutout' Tcl command made sure that when an error pop-up then it returns with a "fail" string
 - made sure when running scripts from the interface that if a command will generate an error then the script is aborted
+- added a new Tcl command named 'list_pp' which lists the available preprocessor names
 
 17.01.2022
 
diff --git a/app_Main.py b/app_Main.py
index 61829711..e2faa552 100644
--- a/app_Main.py
+++ b/app_Main.py
@@ -629,7 +629,7 @@ class App(QtCore.QObject):
                                   'export_gcode', 'export_gerber', 'export_svg', 'ext', 'exteriors', 'follow',
                                   'geo_union', 'geocutout', 'get_bounds', 'get_names', 'get_path', 'get_sys', 'help',
                                   'interiors', 'isolate', 'join_excellon',
-                                  'join_geometry', 'list_sys', 'milld', 'mills', 'milldrills', 'millslots',
+                                  'join_geometry', 'list_sys', 'list_pp', 'milld', 'mills', 'milldrills', 'millslots',
                                   'mirror', 'ncc',
                                   'ncr', 'new', 'new_geometry', 'new_gerber', 'new_excellon', 'non_copper_regions',
                                   'offset',
diff --git a/tclCommands/TclCommandListPP.py b/tclCommands/TclCommandListPP.py
new file mode 100644
index 00000000..7dadf1ff
--- /dev/null
+++ b/tclCommands/TclCommandListPP.py
@@ -0,0 +1,51 @@
+# ##########################################################
+# FlatCAM: 2D Post-processing for Manufacturing            #
+# File Author: Marius Adrian Stanciu (c)                   #
+# Date: 1/18/2022                                         #
+# MIT Licence                                              #
+# ##########################################################
+
+from tclCommands.TclCommand import *
+
+
+class TclCommandListPP(TclCommand):
+    """
+    Tcl shell command to get the list of available preprocessors
+
+    example:
+        list_pp
+    """
+
+    # List of all command aliases, to be able use old names for backward compatibility (add_poly, add_polygon)
+    aliases = ['list_pp', 'listpp']
+
+    description = '%s %s' % ("--", "Outputs in Tcl Shell the list with the names of available preprocessors.")
+
+    # Dictionary of types from Tcl command, needs to be ordered
+    arg_names = collections.OrderedDict([
+    ])
+
+    # Dictionary of types from Tcl command, needs to be ordered , this  is  for options  like -optionname value
+    option_types = collections.OrderedDict([
+    ])
+
+    # array of mandatory options for current Tcl command: required = {'name','outname'}
+    required = []
+
+    # structured help for current command, args needs to be ordered
+    help = {
+        'main': "Returns the list with the names of available preprocessors.\n",
+        'args': collections.OrderedDict([
+        ]),
+        'examples': ['list_pp', 'listpp']
+    }
+
+    def execute(self, args, unnamed_args):
+        """
+
+        :param args:
+        :param unnamed_args:
+        :return:
+        """
+        ret_val = list(self.app.preprocessors.keys())
+        return str(ret_val)
diff --git a/tclCommands/__init__.py b/tclCommands/__init__.py
index b1d04fd6..f7845495 100644
--- a/tclCommands/__init__.py
+++ b/tclCommands/__init__.py
@@ -37,6 +37,7 @@ import tclCommands.TclCommandFollow
 import tclCommands.TclCommandJoinExcellon
 import tclCommands.TclCommandJoinGeometry
 import tclCommands.TclCommandListSys
+import tclCommands.TclCommandListPP
 import tclCommands.TclCommandMillDrills
 import tclCommands.TclCommandMillSlots
 import tclCommands.TclCommandMirror