Born in Pisa, Guido Cappello moved to Gorizia at a young age, then in the 1960s to Milan. By profession he was an accountant. In the 1960s and 1970s Guido Cappello was one of the strongest Italian chess players. In 1960 he won the Italian Chess Championship in Perugia, ahead to Alberto Giustolisi, Federico Norcia and Enrico Paoli. Guido Cappello was awarded the title of National Chess Master in the same year. In the 1963 Italian Chess Championship in Imperia he still touched the title, ranking on equal points with the winner Ennio Contedini, who prevailed by technical play-off. Guido Cappello later achieved other excellent placings in this tournament: shared 3rd–5th place in 1965, 3rd place in 1967 and 1968, shared 2nd–4th place in 1972. Guido Cappello has had several successes in International Chess Tournaments, ranked 3rd in Savona (1967) and in Milan (1968). In 1964 he took part in the Baku International Chess tournament and scored 5,5 from 11.International Tournament- Baku November-December 1964
