Based in Seattle and reporting to Bob Moore, the president and executive creative director, Tembulkar's remit will include working on clients such as T-Mobile, Dish TV and RealNetworks.
Tembulkar was at TBWA for ten months, having joined from Bartle Bogle Hegarty Asia-Pacific, where he was a creative director for four-and-a-half years.
His exit follows the departures of his fellow creatives Marcus Rebeschini and Robert Kleman, who left to take up positions at TBWA's New York office.