William Yockey, 28, of Norfolk, Va., told ABC News his family was sightseeing in Washington when his daughter entered a unisex bathroom at a Starbucks near the National Mall.
Yockey said the store manager called police after his daughter saw a video camera while washing her hands in the bathroom sink.
Police found a Colby digital video camera under a U-shaped drain pipe in the restroom and confirmed that it was on and recording.
Yockey is seeking $1 million from Starbucks for negligence, failure to supervise employees, breach of privacy and failure to inspect facilities in a timely manner.
Starbucks spokesman Alan Hilowitz said the company responded appropriately.
It wasn't the first time Starbucks had problems with cameras in its restrooms.
Previous incidents have occurred in California, Florida and New York.