Paula Brien was last seen leaving a bar at Sixth and Mission streets shortly after midnight on June 18, 2001, police said.
Brien left the bar with a man and was found murdered two hours later less than a mile away at 455 Harriet St.
The man she left the bar with was described as white, 6 feet tall, weighing 200 pounds, with black hair and a tattoo of a skull and cross bones on his right upper arm.
At the time of the murder, he was described as being between 35 and 40 years old and was seen driving a red vehicle, police said.
Anyone with information is asked to call police at (415) 575-4444 or text message a tip to TIP411.