Cramer-Krasselt will handle creative and media planning and buying for Atlanta-based Porsche Cars North American, Inc., a subsidiary of the German luxury automaker.
The company chose Cramer-Krasselt after a four-month review of 20 agencies.
"Our decision to go with Cramer-Krasselt was based on seeking new and innovative approaches to marketing our unique products to a difficult-to-reach audience," said David Pryor, the subsidiary's vice president of marketing in a statement.
It is a huge contract for Cramer-Krasselt, which has never handled a national automotive account.
The agency may be best known for its work with Corona.
"Everyone is thrilled," said Cramer-Krasselt's general manager Karen Seamen. "It's a fabulous piece of business."
It was the second big snare for Cramer-Krasselt in six days. The agency was also chosen by Bissell to market vacuum cleaners and other products.