This is both a college town and a popular backpacker and adventure-tourism destination, so you'll find a relatively active nightlife here. In general, the bars get going around 9pm and shut down around midnight to 2am. Discos get cranking around 10pm and close their doors between 3 and 4am. None of the bars in town charge a cover; some of the dance clubs will occasionally charge BsF1 to BsF5 ($45¢-$2.35/25p-£1.14) admittance, but it will usually get you a drink or two.
La Cucaracha Racing Bar, Alto Prado, and El Bodegón de Pancho, Centro Comercial Mamayeya, are both multienvironment establishments and two of the more popular nightspots in town. El Hoyo Queque and Grada's Sports Bar, Avenida 4 and Calle 19, are two happening bars almost always overflowing with the local college crowd; they're located straight across the street from each other. For a mellower scene, try T'Café, on the corner of Avenida 3 and Calle 29, across from Heladería Coromoto.