This self-service fish restaurant in the heart of Trastevere also has two other branches elsewhere: one on Via Pietralata in north-east Rome, the other at Fregene by the sea.
The formula is the same in each venue: customers select their meal directly from a fish counter. Fried or grilled, the fish is always fresh and generally cheap.
The Trastevere restaurant is open for dinner every day from 19.30-01.00. It is also open for lunch on Sat-Sun from 13.00-16.00.
For full details of all three Fish Market venues see website.