San Pedro de Atacama is remote by almost any standard. The nearest city is Calama, about 100 kilometres northwest at 2,250 metres. Calama has a domestic airport (IATA: CJC) with regular flights to Santiago (90 minutes) and connections to other Chilean cities. The airport is used by mining companies serving the copper industry of northern Chile, so capacity is reasonable. From Calama airport, shared vans or taxis to San Pedro take about 90 minutes on a paved road through the desert.
Long-distance buses connect Calama to Antofagasta (4 hours), Santiago (22 hours overnight), and other Chilean cities. From Calama, minibuses and shared taxis run regularly to San Pedro throughout the day.
San Pedro can also be reached from Argentina (via the Paso de Jama border crossing, 4 hours from Salta by road) and from Bolivia (via the Paso Hito Cajón crossing, for access to the Bolivian altiplano). These are spectacular but sometimes unreliable routes depending on road conditions and weather — check before attempting them in the rainy season (November to March).
There is a small airstrip (Aeródromo de San Pedro de Atacama) for charter and light aircraft, but no scheduled commercial service at time of writing.