diff --git a/pydoctor/driver.py b/pydoctor/driver.py
index c520d07..62ec1cd 100644
--- a/pydoctor/driver.py
+++ b/pydoctor/driver.py
@@ -1,7 +1,7 @@
 """The command-line parsing and entry point."""
 
 from pydoctor import model, zopeinterface
-import sys, os
+import sys, os, re
 
 def error(msg, *args):
     if args:
@@ -98,6 +98,11 @@ def getparser():
         metavar='MODULE', default=[],
         help=("Add a module to the system.  Can be repeated."))
     parser.add_option(
+        '--exclude', action='append', dest='exclude',
+        metavar='EXCLUDEDPATTERN', default=[],
+        help=("Exclude packages and modules matching this regex.  "
+              "Can be repeated to exclude multiple packages/modules"))
+    parser.add_option(
         '--prepend-package', action='store', dest='prependedpackage',
         help=("Pretend that all packages are within this one.  "
               "Can be used to document part of a package."))
@@ -295,6 +300,14 @@ def main(args):
             else:
                 options.makehtml = False
 
+        # step 1.9: make regex excludes
+        if options.exclude:
+            try:
+                options.exclude = map(re.compile, options.exclude)
+            except re.error, e:
+                error("Exclude options must be valid regular "
+                      "expressions.  Error: %s" % e)
+
         # step 2: add any packages and modules
 
         if args:
diff --git a/pydoctor/model.py b/pydoctor/model.py
index caa15c3..1a55828 100644
--- a/pydoctor/model.py
+++ b/pydoctor/model.py
@@ -546,6 +546,10 @@ class System(object):
         if not os.path.exists(os.path.join(dirpath, '__init__.py')):
             raise Exception("you must pass a package directory to "
                             "addPackage")
+ 
+        if self.shouldExclude(dirpath):
+            return
+        
         package = self.Package(self, os.path.basename(dirpath),
                                None, parentPackage)
         self.addObject(package)
@@ -558,8 +562,18 @@ class System(object):
                 if os.path.exists(initname):
                     self.addPackage(fullname, package)
             elif fname.endswith('.py') and not fname.startswith('.'):
+                if self.shouldExclude(fullname):
+                    continue
                 self.addModule(fullname, package)
 
+    def shouldExclude(self, name):
+        '''Return True if this name is excluded'''
+        basename = os.path.basename(name)
+        for exclude in self.options.exclude:
+            if exclude.match(basename):
+                return True
+        return False
+
     def handleDuplicate(self, obj):
         '''This is called when we see two objects with the same
         .fullName(), for example: