Esko Saira made his international début at the 1972 Olympic Winter Games where he won a silver in the relay, which he would also repeat at the next Olympics. Individually he was sixth in the 20 km at both of those Olympics. Saira won his only individual international medal at the 1975 World Championships, when he won a bronze in the 20 km. Saira was very successful at the Nordic Championships, where he won six gold medals – two in the individual 20 km in 1973 and 1975 and four in the relay in 1971, 1973, and 1975-76. Saira also won two Finnish titles in biathlon – in 1972 in the 20 km and in 1975 in the 10 km and two Finnish titles in modern triathlon, which consists of running, swimming and shooting, in 1969 and 1970.