Llullaillaco has been active in historical time, with the last eruption occurring in the late 19th century. Eruptions were recorded in February 1854, September 1868, and May 1877, involving two explosive eruptions and one with lava flows. According to a report in 1899, during the 1868 eruption large fissures opened on its slopes. The last eruption consisted of smoking reported at the time of the 1877 Iquique earthquake.