The first ascent of the Aiguille de Bionnassay was undertaken on 28 July 1865 by Florence Crauford Grove, Edward N. Buxton and Reginald S. McDonald, with guides Jean Pierre Cachat and Michel Payot. They ascended the north-west face to reach the ridge above the Aiguille de Tricot, from where they continued to the knife-edged summit ridge, arriving in a thunderstorm. A detailed account is given below.