I've never been to lisbon, but I went to prague with a vegan friend who despaired that every restaurant had the same, single, vegetarian option: battered, deep fried cheese.

being a vegetarian, I think you'll find more options in Lisbon. Both cities are simply amazing though, and you can't go wrong with either. Have fun...

go to berlin instead, its ace

hmmmm, vegetariaism doesn't exist in Prague, but Lisbon could be unbearably hot and crowded in June. That doesn't help you, huh?! hmmm, how about Bruges - said to be the most beautiful city in Europe - with warm temperatures in June and French-influenced cuisine, without the crowds of Paris or Prague

Lisbon, hands down, but you need to be out late to really appreciate the city. Its comes alive after midnight.

sp_999

Screw both of those places. What's wrong with Ocean City?

Cheese is definately the only vegitarian option in Prague, although it is gorgeous. I'm told however that all the locals clear out of the city in the summer as it gets smoggy. Apparently.

Don't know anything about Lisbon.