The town of Nafpaktos gets pretty lively at night. The most popular nightlife spot of Nafpaktos is the port, lined up with nice cafe bars that stay till late and play soft music. On the hill above the town. just below the castle, there are two nice bars with night view to Nafpaktos and the opposite town of Patra.
The beach place of Gribovo, just a few minutes walk from the port of Nafpaktos, is a nice promenade lined up with taverns and calm cafeterias. So is the other beach promenade of Nafpaktos called Psani, also lined up with grill taverns that stay till after midnight.