Panajachel has a fairly active nightlife. For the past 15 years, my favorite place has been the Circus Bar (tel. 502/7762-2056), Avenida Los Arboles, which has a relaxed vibe, simple menu, and decor to match the joint's name. They also frequently have live music. This is also the first place I ever tried Ron Zacapa, Guatemala's world-class 23-year-old aged rum. Circus Bar, just north of Calle Principal, is located in what's considered Panajachel's mini-Zona Viva.
Of the bars on Calle Santander, I like the Maktub'ar Café, which has a relaxed, almost beach-bar feel, and Pana Rock Café (tel. 502/7762-2194), which is a takeoff on the Planet Rock chain.
For a mellow night, La Terraza, Calle Santander (tel. 502/7762-0041), is a second-floor bar and restaurant area with a balcony overlooking Calle Santander.
For loud and late-night dancing, try Sócrates Disco, Calle Principal (tel. 502/7762-1015); El Aleph, Avenida Los Arboles (tel. 502/7762-0192); or El Chapiteau Discoteque, Avenida Los Arboles (tel. 502/7762-0374).