The Naschmarkt is the best and most famous market in all of Vienna. But it's not only about the stands, which close down at nighttime. At night (Nightlife in the Naschmarkt), many places to eat are still open, especially on the North Eastern half of the market and the areas immediately surrounding.
One place that will still be open late into the night is the super-trendy modern Asian restaurant and cocktail bar, ON Market. The restaurant is extremely visually stimulating, with colorful textile artworks covering its walls, and food that is exquisite and quite diverse.
Another restaurant whose Sichuan cuisine you won't to miss is ChinaBar an der Wien. You should also checkout the Naschmarkt Deli, whose stools fill up with people grabbing a bite to eat long after the market has closed.
A great nighttime pleasure is taking a walk along the South Western part of the Naschmarkt. It's clean and quiet and has a special, relaxing ambiance.