Martin Clunes will return for another batch of eight episodes as Dr Martin Ellingham, with the comedy drama expected to anchor ITV's autumn schedule of 2013.
Filming will begin next spring on location in Port Isaac with all regular members of the cast returning to the programme.
At the end of the last run, Clunes's alter ego reconciled with long-time love interest Louisa Glasson (Caroline Catz) after rescuing their son James from a narcotized pharmacist Sally Tishell.
Clunes said in a statement: "I'm thrilled to be going back to the beautiful North Cornish coast to shoot series six of Doc Martin.
"Our challenge this season will be to force Louisa and the doctor to live together with Baby James which as far as I can see has disaster written all over it. And then there's the dog and Dame Eileen but not necessarily in that order!"
Doc Martin posted viewing figures of almost 9 million for its fifth series in 2010.
The hit show, which has been on air for seven years, has been regularly screened every two years since 2005.