During April 1906, Perret and Matteucci observed a major eruption of Vesuvius, during which Perret took numerous photographs and made many observations of eruptive phenomena, including St Elmo's Fire. Perret eventually published a major monograph on this eruption in 1924. In her obituary of Perret, Mildred Giblin wrote that Perret's monograph on the Vesuvius was the clearest and most comprehensive report ever on a volcanic eruption and its aftermath published. By the end of the first decade of the 20th century Perret had also visited the volcanoes of Kilauea, Stromboli, Etna, Mount Teide and Sakurajima. In 1909 Perret suggested to the geophysicists Thomas Jaggar from Massachusetts Institute of Technology and Reginald A. Daly of Harvard University to establish a continuous monitoring station at Kilauea. Perret spent four months on Kilauea in 1911, where he began to make the first long-term observations of activity from the edge of the crater Halemaʻumaʻu. The station was the forerunner of the Hawaiian Volcano Observatory, which was built by Thomas Jaggar the following year. When Mount Pelée on the French Caribbean island of Martinique became active again in 1929, some years after the devastating eruption of 1902 Perret was one of the first scientists on site. During the three years of volcanic activity, from 1929-1932, he conducted numerous investigations and in 1931 he built a small observation hut on the Morne Lenard above the valley of the Riviere Blanch as the first permanent station on the mountain. Perret published a monograph on the Pelee eruptions in 1936. During his extended stay on Martinique, Perret raised funds to establish a volcanological museum in St Pierre, to 'tell the story of the Modern Pompeii'. The founders of this enterprise included a local rum merchant, Victor Depaz, and philanthropists Vincent Astor, William L Mellon and George F Baker. The Musée Franck A. Perret volcanological museum opened in 1933, and re-opened in 2019 after renovations as the Frank Perret Museum - Memorial to the 1902 Catastrophe.