The Oregonian newspaper said the plaintiff is seeking $2 million from Oregon Health & Science University for "worry and emotional distress" over the fertility clinic's mistake.
The man had been receiving treatment at the clinic when he gave a sperm sample to clinic workers in September 2005. The suit contends his sperm was given to a woman who was to receive sperm from an anonymous donor and she became pregnant, the newspaper said.
"In the 31-year history of the OHSU fertility clinic, this situation has never occurred previously," OHSU said in a statement. "The clinic performs about 1,000 inseminations each year ... . Changes have been implemented to protect against a recurrence of this error."