He has appeared in several productions at Ensemble Theatre including Lovers, The Comedians, Boy Meets Girl, 6 Rms Riv Vu, Sonny and Same Difference, and most recently Wrong Turn at Lungfish in 2008.
His work at the Melbourne Theatre Company includes Born Yesterday, Twelfth Night, Into the Woods, Assassins, The Glass Menagerie, The Real Thing, Serious Money, High Society, Art, Take Me Out and Boy Gets Girl.
Plays for Nimrod Theatre Company include Young Mo, Volpone, Inside the Island, The Orestia, Clouds, Romeo and Juliet, Henry IV and Comedy of Errors.
McTernan is also well known for his work in music theatre with major stage roles in Grease, Godspell, Guys and Dolls, Sunset Boulevard, The History of Australia, Joseph and the Amazing Technicolour Dreamcoat, Shout, Into the Woods, and Assassins.
The Story of Johnny O'Keefe Other television roles include City Homicide, All Saints, Blue Heelers, Stingers, Something in the Air and Scooter: Secret Agent.