diff --git a/README.md b/README.md
index 96da7ab..9a29134 100644
--- a/README.md
+++ b/README.md
@@ -36,6 +36,7 @@ Options:
   -p, --pass <pass>              Password to use for authentication
   -o, --port <port>              Port to connect to
   -t, --timeout <timeout>        Connection timeout in ms
+  -D, --dsn <old style dsn>      Classic DSN connection string
   -d, --database <database>      Database to connect to
   -q, --query <query>            The query to execute
   -v, --tdsVersion <tdsVersion>  Version of tds protocol to use [7_4, 7_2, 7_3_A, 7_3_B, 7_4]
@@ -48,6 +49,13 @@ To connect to a SQL Server instance in Azure invoke mssql as follows
 mssql -s abcdef.database.windows.net -u username@abcdef -p thepassword -d mydatabase -e
 ```
 
+A classic style DSN connection string may be used in lieu of all other
+options
+
+``` bash
+mssql -D "Server=localhost,1433;UID=DOMAIN\\user;PWD=password"
+```
+
 You will get a prompt as follows:
 ```bash
 Connecting to abcdef.database.windows.net...done
diff --git a/lib/options.js b/lib/options.js
index 498dc3c..602794b 100644
--- a/lib/options.js
+++ b/lib/options.js
@@ -27,6 +27,7 @@
                     .option('-o, --port <port>', 'Port to connect to')
                     .option('-t, --timeout <timeout>', 'Connection timeout in ms')
                     .option('-T, --requestTimeout <timeout>', 'Request timeout in ms')
+                    .option('-D, --dsn <old-style dsn>', 'DSN connection string')
                     .option('-d, --database <database>', 'Database to connect to')
                     .option('-q, --query <query>', 'The query to execute')
                     .option('-v, --tdsVersion <tdsVersion>', 'Version of tds protocol to use [7_4, 7_2, 7_3_A, 7_3_B, 7_4]')
@@ -39,7 +40,7 @@
                 this.env = env;
                 this.args = {};
                 _.extend(this.args, _.pick(program, 'server', 'user', 'pass',
-                    'port', 'requestTimeout', 'timeout',
+                    'port', 'requestTimeout', 'timeout', 'dsn',
                     'database', 'query', 'tdsVersion',
                     'encrypt', 'format', 'config'));
 
@@ -74,6 +75,7 @@
                 user: env.SQLCLI_USER || 'sa',
                 pass: env.SQLCLI_PASSWORD,
                 server: env.SQLCLI_SERVER || 'localhost',
+                dsn: env.SQLCLI_DSN,
                 database: env.SQLCLI_DATABASE,
                 port: env.SQLCLI_PORT,
                 timeout: env.SQLCLI_TIMEOUT,
@@ -84,7 +86,8 @@
 
             config = _.extend({}, defaults, config, args);
 
-            var connectInfo = {
+            var connectInfo = !config.dsn 
+              ? {
                 user: config.user,
                 password: config.pass,
                 server: config.server,
@@ -100,7 +103,8 @@
                     max: 1,
                     min: 1
                 }
-            };
+              }
+          : config.dsn ;
 
             return connectInfo;
         }