diff --git a/README.rst b/README.rst
index da3c697..04fdec2 100644
--- a/README.rst
+++ b/README.rst
@@ -11,6 +11,12 @@ A simple parser for OpenStack microversion headers::
         headers, service_type='compute',
         legacy_headers=['x-openstack-nova-api-version'])
 
+    # If headers are not already available, a dict of headers
+    # can be extracted from the WSGI environ
+    headers = microversion_parse.headers_from_wsgi_environ(environ)
+    version = microversion_parse.get_version(
+        headers, service_type='placement')
+
 It processes microversion headers with the standard form::
 
     OpenStack-API-Version: compute 2.1
diff --git a/microversion_parse/__init__.py b/microversion_parse/__init__.py
index cb3fe63..6fc8071 100644
--- a/microversion_parse/__init__.py
+++ b/microversion_parse/__init__.py
@@ -16,6 +16,7 @@ __version__ = '0.1.1'
 import collections
 
 
+ENVIRON_HTTP_HEADER_FMT = 'http_{}'
 STANDARD_HEADER = 'openstack-api-version'
 
 
@@ -63,7 +64,7 @@ def check_legacy_headers(headers, legacy_headers):
     """Gather values from old headers."""
     for legacy_header in legacy_headers:
         try:
-            value = headers[legacy_header.lower()]
+            value = _extract_header_value(headers, legacy_header.lower())
             return value.split(',')[-1].strip()
         except KeyError:
             pass
@@ -73,7 +74,7 @@ def check_legacy_headers(headers, legacy_headers):
 def check_standard_header(headers, service_type):
     """Parse the standard header to get value for service."""
     try:
-        header = headers[STANDARD_HEADER]
+        header = _extract_header_value(headers, STANDARD_HEADER)
         for header_value in reversed(header.split(',')):
             try:
                 service, version = header_value.strip().split(None, 1)
@@ -100,3 +101,31 @@ def fold_headers(headers):
         folded_headers[header] = ','.join(value)
 
     return folded_headers
+
+
+def headers_from_wsgi_environ(environ):
+    """Extract all the HTTP_ keys and values from environ to a new dict.
+
+    Note that this does not change the keys in any way in the returned
+    dict. Nor is the incoming environ modified.
+
+    :param environ: A PEP 3333 compliant WSGI environ dict.
+    """
+    return {key: environ[key] for key in environ if key.startswith('HTTP_')}
+
+
+def _extract_header_value(headers, header_name):
+    """Get the value of a header.
+
+    The provided headers is a dict. If a key doesn't exist for
+    header_name, try using the WSGI environ form of the name.
+
+    Raises KeyError if neither key is found.
+    """
+    try:
+        value = headers[header_name]
+    except KeyError:
+        wsgi_header_name = ENVIRON_HTTP_HEADER_FMT.format(
+            header_name.replace('-', '_'))
+        value = headers[wsgi_header_name]
+    return value
diff --git a/microversion_parse/tests/test_headers_from_wsgi_environ.py b/microversion_parse/tests/test_headers_from_wsgi_environ.py
new file mode 100644
index 0000000..525ac6e
--- /dev/null
+++ b/microversion_parse/tests/test_headers_from_wsgi_environ.py
@@ -0,0 +1,61 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import testtools
+
+import microversion_parse
+
+
+class TestHeadersFromWSGIEnviron(testtools.TestCase):
+
+    def test_empty_environ(self):
+        environ = {}
+        expected = {}
+        self.assertEqual(
+            expected,
+            microversion_parse.headers_from_wsgi_environ(environ))
+
+    def test_non_empty_no_headers(self):
+        environ = {'PATH_INFO': '/foo/bar'}
+        expected = {}
+        found_headers = microversion_parse.headers_from_wsgi_environ(environ)
+        self.assertEqual(expected, found_headers)
+
+    def test_headers(self):
+        environ = {'PATH_INFO': '/foo/bar',
+                   'HTTP_OPENSTACK_API_VERSION': 'placement 2.1',
+                   'HTTP_CONTENT_TYPE': 'application/json'}
+        expected = {'HTTP_OPENSTACK_API_VERSION': 'placement 2.1',
+                    'HTTP_CONTENT_TYPE': 'application/json'}
+        found_headers = microversion_parse.headers_from_wsgi_environ(environ)
+        self.assertEqual(expected, found_headers)
+
+    def test_get_version_from_environ(self):
+        environ = {'PATH_INFO': '/foo/bar',
+                   'HTTP_OPENSTACK_API_VERSION': 'placement 2.1',
+                   'HTTP_CONTENT_TYPE': 'application/json'}
+        expected_version = '2.1'
+        headers = microversion_parse.headers_from_wsgi_environ(environ)
+        version = microversion_parse.get_version(headers, 'placement')
+        self.assertEqual(expected_version, version)
+
+    def test_get_version_from_environ_legacy(self):
+        environ = {'PATH_INFO': '/foo/bar',
+                   'HTTP_X_OPENSTACK_PLACEMENT_API_VERSION': '2.1',
+                   'HTTP_CONTENT_TYPE': 'application/json'}
+        expected_version = '2.1'
+        headers = microversion_parse.headers_from_wsgi_environ(environ)
+        version = microversion_parse.get_version(
+            headers, 'placement',
+            legacy_headers=['x-openstack-placement-api-version'])
+        self.assertEqual(expected_version, version)