At any time on a balmy evening you'll have your work cut out to beat the fashionistas competing for tables beneath the ancient fig tree that gives its name to this square and its bar. Along with the Bar della Pace just around the corner, this has been the place for the smart set for decades. The neon-lit interior with its kitschy furnishings is rather bare but still manages to feel chic.

Open Mon–Sat 8:30 a.m.–2 a.m., Sun 3 p.m.–2:30 a.m.

When it opened in 2004, Crudo made a big thing of its rather pricey upstairs raw-seafood restaurant, but it's the downstairs bar that has won the popular vote. Filled with 1960s and '70s cast-off chairs from various Italian ministries, and dominated by a long bar backed by Francis Bacon–esque frescoed portraits, this stylish aperitivo and after-dinner hangout is a good alternative to the increasingly down-market bar scene in nearby Campo De' Fiori. No matter that the barman looks like an AC/DC fan circa 1976—he certainly knows how to mix a dry martini (try the version with Old Raj, a saffron-tinted connoisseur's gin from Scotland). Since 2006, Crudo has become an official Ferrari Lounge—the name referring not to the car but to the spumante, considered by many to be Italy's top sparkling wine, which can be ordered straight or in various Champagne-style cocktails.

Open Mondays through Fridays 12:30 to 3:30 pm and 8 pm to 2 am, Saturdays 8 pm to 2 am.

So '60s Space Age is this stunningly white club that you might not even notice that you're in a cavern dug into a heap of ancient amphora shards. But that's what Monte Testaccio is. There's nothing ancient about the music, which ranges from electronica to hip-hop and R&B, with visits from big-name DJs. There's a garden too, but as Fake closes from June to September, there's little chance to appreciate it.

Open Wed, Thur 11:30 p.m.–4 a.m.; Fri, Sat midnight–4 a.m.; Sun 7 p.m.–2 a.m.

In a former mechanic's workshop on the river bank in Trastevere, "Brakes and Clutch" is a new arrival on the Rome bar scene. It starts heating up soon after opening time (6 p.m.), when peckish locals descend on a table groaning with free aperitivo nibbles. Its denizens are young and boho-chic, the ambience laid-back and friendly. When the bar gets too crowded, the little square outside becomes an extension of the venue.

Open daily 6 p.m.–2 a.m.

When Leo and crew were in Rome to shoot Gangs of New York, they came to Goa postfilming to let off steam. The ethno-chic club in the down-at-heel-looking but definitely up-and-coming Ostiense district is still going strong. Housed in a huge garage, Goa draws some of the world's best DJs to mix hip-hop, house, and tribal sounds.

Open Tues–Sun 11 p.m.–5 a.m.

Mod, Conran-inspired 'Gusto—with its restaurant, pizzeria, and kitchenware shop—caused a sensation when it opened in 1998, but it's looking rather frayed around the edges these days. The wine bar, with its entrance out back in Via della Frezza, remains a lively place for an after-dinner (or after-film) drink—though the website's claim to offer 1,500 different labels is marred by the fact that the depleted cellars are probably out of your first three or so choices. There's live jazz or soul some evenings, and you can soak up the wine with plates of cold cuts or cheese.

You may have some trouble getting past the obnoxious doormen, which only enhances the pleasure and surprise if you're successful. Because, despite being the disco of choice for what looks like a very snooty crowd, La Maison plays great lounge and R&B music in a decidedly welcoming ambience of dark red walls and comfy sofas. It's very elegant; make sure you are too, or you'll never get in.

Open Tue–Thur, Sun 11 p.m.–3:30 a.m.; Fri, Sat midnight–5 a.m.

Campo de' Fiori is one big drinking spot, but this wine bar was the first, and remains the best. While rowdy groups of visiting students pile into the other drinking holes, locals mix with visitors in La Vineria's bottle-lined interior or grab tables outside to watch the antics in this ever-bustling square. Perfectly acceptable wine starts at about $1.90 a glass. Pre-dinner, the clientele consists of busy locals grabbing a glass with friends on their way home from work; as the evening wears on, the scene gets slightly seedier but remains lively.

Open Mon–Sat 9 a.m.–2 a.m.

Rome's newest, most happening club is in an immense underground space in a residential district not far from the basilica of San Giovanni in Laterano. The program is all-encompassing, ranging from themed nights (including toga parties, of course) to guest DJ visits. A vintage clothes and bric-a-brac market on Sunday evening gives way to jazz and other live acts later. You need to sign the online guest book in order to get in.

Open Thur–Sat 10 p.m.–3 a.m.; Sun 6 p.m.–3 a.m.

It's no easy task finding this bar in a tiny square off Via dei Coronari. You'll know when you do, though: Piazza Montevecchio is an extension of the place, and the alternative, artsy crowd spills out across the square (much to the annoyance of neighbors, who have been known to throw water over rowdy revelers). Well-mixed cocktails, a small but good selection of wines by the glass, a large aperitivo buffet, and a decidedly relaxed vibe make this a great place to kill a couple of hours.

Open daily 6 p.m.–2 a.m.

At this sister venue to the Amsterdam hot spot, it's best to miss the overpriced dinner and uneven floor show and to arrive after hours to drink and dance. Model types lounge on huge white mattresses, and tanned Italian gods take up their positions in the sexy Rouge Bar. You can even get a massage while you sip your mojito. The cutting-edge design in a crumbling old palazzo captures the Roman ability to mix old and new to ravishing effect, but the place is no longer a discovery.

Open Tue–Sun from 8:30 p.m.