This paper is an initial appraisal of the effects of the M = 7.8 earthquake centred near San Antonio, Chile, which occurred on 3 March 1985. The author arrived in Chile six days after the main shock and spent a week investigating as many aspects as possible. The earthquake caused heavy damage to a large area including the major cities of San Antonio, Valparaiso and Santiago, and resulted in 700,000 people being made homeless. Damage to engineered structures appeared to be less than might be expected for an earthquake of this magnitude, but non-structural damage was heavy. Eight or nine accelerographs recorded the shaking in different parts of the more heavily affected area and should help enrich the findings of the numerous valuable post-earthquake studies which will be possible.