diff --git a/garminexport/garminclient.py b/garminexport/garminclient.py
index d6e5fdc..a443a22 100755
--- a/garminexport/garminclient.py
+++ b/garminexport/garminclient.py
@@ -12,6 +12,7 @@ from StringIO import StringIO
 import sys
 import zipfile
 import dateutil
+import os.path
 
 #
 # Note: For more detailed information about the API services
@@ -341,3 +342,63 @@ class GarminClient(object):
         # and cannot be exported to fit
         return orig_file if fmt=='fit' else None
 
+    @require_session
+    def upload_activity(self, file, format=None, name=None, description=None, activity_type=None, private=None):
+        """Upload a GPX, TCX, or FIT file for an activity.
+
+        :param file: Path or open file
+        :param format: File format (gpx, tcx, or fit); guessed from filename if None
+        :param name: Optional name for the activity on Garmin Connect
+        :param description: Optional description for the activity on Garmin Connect
+        :param activity_type: Optional activityType key (lowercase: e.g. running, cycling)
+        :param private: If true, then activity will be set as private.
+        :returns: ID of the newly-uploaded activity
+        :rtype: int
+        """
+
+        if isinstance(file, basestring):
+            file = open(file, "rb")
+
+        # guess file type if unspecified
+        fn = os.path.basename(file.name)
+        _, ext = os.path.splitext(fn)
+        if format is None:
+            if ext.lower() in ('.gpx','.tcx','.fit'):
+                format = ext.lower()[1:]
+            else:
+                raise Exception(u"could not guess file type for {}".format(fn))
+
+        # upload it
+        files = dict(data=(fn, file))
+        response = self.session.post("https://connect.garmin.com/proxy/upload-service-1.1/json/upload/.{}".format(format),
+                                     files=files)
+
+        # check response and get activity ID
+        if response.status_code != 200:
+            raise Exception(u"failed to upload {} for activity: {}\n{}".format(
+                format, response.status_code, response.text))
+
+        j = response.json()
+        if len(j["detailedImportResult"]["failures"]) or len(j["detailedImportResult"]["successes"])!=1:
+            raise Exception(u"failed to upload {} for activity")
+        activity_id = j["detailedImportResult"]["successes"][0]["internalId"]
+
+        # add optional fields
+        fields = ( ('name',name,("display","value")),
+                   ('description',description,("display","value")),
+                   ('type',activity_type,("activityType","key")),
+                   ('privacy','private' if private else None,("definition","key")) )
+        for endpoint, value, path in fields:
+            if value is not None:
+                response = self.session.post("https://connect.garmin.com/proxy/activity-service-1.2/json/{}/{}".format(endpoint, activity_id),
+                                             data={'value':value})
+                if response.status_code != 200:
+                    raise Exception(u"failed to set {} for activity {}: {}\n{}".format(
+                        endpoint, activity_id, response.status_code, response.text))
+
+                j = response.json()
+                p0, p1 = path
+                if p0 not in j or j[p0][p1] != value:
+                    raise Exception(u"failed to set {} for activity {}\n".format(endpoint, activity_id))
+
+        return activity_id
diff --git a/upload_activity.py b/upload_activity.py
new file mode 100644
index 0000000..e03440f
--- /dev/null
+++ b/upload_activity.py
@@ -0,0 +1,66 @@
+#! /usr/bin/env python
+"""A program that uploads an activity file to a Garmin
+Connect account.
+"""
+import argparse
+import getpass
+from garminexport.garminclient import GarminClient
+import logging
+import sys
+import traceback
+
+logging.basicConfig(
+    level=logging.INFO, format="%(asctime)-15s [%(levelname)s] %(message)s")
+log = logging.getLogger(__name__)
+
+LOG_LEVELS = {
+    "DEBUG": logging.DEBUG,
+    "INFO": logging.INFO,
+    "WARNING": logging.WARNING,
+    "ERROR": logging.ERROR
+}
+"""Command-line (string-based) log-level mapping to logging module levels."""
+
+if __name__ == "__main__":
+
+    parser = argparse.ArgumentParser(
+        description=("Uploads an activity file to a Garmin Connect account."))
+    # positional args
+    parser.add_argument(
+        "username", metavar="<username>", type=str, help="Account user name.")
+    parser.add_argument(
+        "activity", metavar="<file>", type=argparse.FileType("rb"),
+        help="Activity file (.gpx, .tcx, or .fit).")
+
+    # optional args
+    parser.add_argument(
+        "--password", type=str, help="Account password.")
+    parser.add_argument(
+        '-N', '--name', help="Activity name on Garmin Connect.")
+    parser.add_argument(
+        '-D', '--description', help="Activity description on Garmin Connect.")
+    parser.add_argument(
+        '-P', '--private', action='store_true', help="Make activity private on Garmin Connect.")
+    parser.add_argument(
+        "--log-level", metavar="LEVEL", type=str,
+        help=("Desired log output level (DEBUG, INFO, WARNING, ERROR). "
+              "Default: INFO."), default="INFO")
+
+    args = parser.parse_args()
+    if not args.log_level in LOG_LEVELS:
+        raise ValueError("Illegal log-level argument: {}".format(
+            args.log_level))
+    logging.root.setLevel(LOG_LEVELS[args.log_level])
+
+    try:
+        if not args.password:
+            args.password = getpass.getpass("Enter password: ")
+        with GarminClient(args.username, args.password) as client:
+            log.info("uploading activity file {} ...".format(args.activity.name))
+            id = client.upload_activity(args.activity, name=args.name, description=args.description, private=args.private)
+            log.info("upload successful: https://connect.garmin.com/activity/{}".format(id))
+    except Exception as e:
+        exc_type, exc_value, exc_traceback = sys.exc_info()
+        log.error(u"failed with exception: %s", e)
+        raise
+