Since the arrival of UNTAC (United Nations Transitional Authority in Cambodia) and the NGOs in 1992, nightlife has Phnom Penh develops rapidly. While it can not compete yet with the nightlife of Bangkok, it has a lively, from dusk-till-dawn nightlife.
The nightlife takes place on roofs, colonial villas, in cocktail bars and cool micro-bars. Some clubs and bars have live music. The music of Phnom Penh is increasing because the amount growing local talent. You can enjoy an endless series of live music ranging from alternative rock, hip hop and reggae to name a few. Top artists have played in night clubs such as Pontoon and Nova.
It's a pretty good party town and offers a variety of places to choose from, including hostess bars, clubs, sports bars, pubs, karaoke bars, discos and more. There are entertainment venues in many parts of the city, but the city is not so big and vast, so it is easy to go from one bar to another. You better go by tuk-tuk or moto (the safest way around at night to travel).
There are several areas in Phnom Penh, where bars and nightlife are concentrated. On the riverfront (Sisowath Quay), in the side streets of the Quay and BKK1 are many bars and restaurants (look at the map below).
In Street 104 and Street 102 are many hostess bars. In Street 136, which is one block away from Sisowath Quay are also lots of hostess bars. Street 51 (between Street 154 and Street 174) are the famous Heart of Darkness, Walkabout, Shanghai and many more entertainment venues.
Near the Independence Monument is the district Boeung Keng Kang (BKK1). BKK1 has long been home to many NGOs, businesses, expats and tourists. Now it is booming with new restaurants, bars and hotels. Hotels in this district tend to the lower middle class and luxury class. Dozens of restaurants have spread across BKK1 and there are international fast food restaurants such as Burger King, Domino's and KFC. Most of the bars and clubs are in the area at the north side of BKK1, especially along Street 278 and 282, and Norodom Boulevard. Street 308, 29 21, and in the micro-bar enclave of Bassac Lane.
Many backpacker cafes and backpacker hostels are located in the BKK1 district. This is the place where you need to be present. Some well-known hangouts for backpackers are the Mini Banana Bar, Blue Dog, White Rabbit, Duplex, Club Love and Mad Monkey.
Along Sisowath Quay (on the river) you'll find o.a Lounge, Chili Blue, Rainbow Bar, Paddy Rice, Foreign Correspondence Club and the Rooftop Bar.