In 1958 Michèle Pialat won her first French swimming titles with victories in the 100 metres breaststroke and the 4 x 100 metres medley relay. Pialat’s performances earned her a spot at that years’ European Championships in Budapest where she reached the final in the medley relay. In 1959 she replicated her national success of the previous year by winning the same two titles, earning her a place at the 1960 Roma Olympics. At the Roma Games she finished 19th in the 200 metres breaststroke and 10th with the French team in the 4 x 100 metres medley relay. Pialat won four more French titles in the medley relay (1961–64), along with two in the 100 metres breaststroke (1962, 1964) and one in the 200 metres breaststroke (1962). At the 1963 Summer Universiade in Porto Alegre, Brazil, she won silver in the 200 metres breaststroke, 4 × 100 metres freestyle relay, and the 4 × 100 metres medley relay.