The local airport, Aeropuerto Diego Aracena, is 41km south of downtown via Ruta 1.
LATAM has several flights a day to Santiago (from CH$90,000, 2½ hours). It also has two weekly flights to Salta, Argentina (around CH$155,000, 1½ hours).
Sky has several daily flights to Santiago (from CH$55,000).
Amaszonas (www.amaszonas.com) flies daily to Arica (from CH$30,000, 40 minutes) and Antofagasta (from CH$45,000, 45 minutes). It also has four weekly flights to La Paz, Bolivia (from CH$65,000), four weekly flights to Salta, Argentina (from CH$190,000, 1½ hours) and five weekly to Asuncion, Paraguay (CH$200,000, two hours).
Minibus transfer from Aeropuerto Diego Aracena to your hotel costs CH$6000; there are a few stands at the airport. Alternatively, shared taxis charge around CH$7000 per person; private cabs cost CH$17,000. Try Taxis Aeropuerto facing the plaza.
The main bus station, Terminal Rodoviario, is at the north end of Patricio Lynch. Most major bus companies, such as Expreso Norte, Pullman and Tur Bus, as well as a few local ones, also have offices clustered around the Mercado Centenario, mainly along Barros Arana. You can reserve tickets here (saving a trek out to the bus terminal), but buses depart from the terminal. Services north and south are frequent, but most southbound services use Ruta 1, the coastal highway to Tocopilla (for connections to Calama) and Antofagasta (for Panamericana connections to Copiapó, La Serena and Santiago).
Several major bus companies, including Ramos Cholele, travel north to Arica and south as far as Santiago.
Sample fares are as follows.
To get to Pica, try one of the agencies on Barros Arana, between Zegers and Latorre. Chacón has several departures daily to Pica (CH$3200, two hours) as does Barreda next door. Santa Angela travels to Pica (CH$3200, two hours), La Tirana (CH$2500, 1½ hours) and Humberstone (CH$2500, 45 minutes).
Several bus companies travel to Bolivian destinations, including La Paz, Cochabamba and Oruro. They're all clustered on one block of Esmeralda, between Amunategui and Martinez. It's not a great neighborhood – take a taxi for early or late departures. For La Paz, Busfer has four departures daily (CH$6000 to CH$10,000, 14 hours), including 4am and 2pm, and Luján also has several daily departures (CH$10,000, 14 hours).
The easiest way to get to Peru is to go first to Arica, then hook up with an international bus there.