Mennea, who was born in Barletta, in the Italian region of Puglia, started his long international athletic career in 1968 when he took part in a junior race in Termoli and he was registered in AVIS Barletta club; in 1971, he won the first of his 14 Italian outdoor titles in the 100 and 200 m. He went on to win two indoor titles in 60 m and 400 m, along with five Mediterranean Games gold medals in 100 m and 200 m. He competed at the European Championships with a third place in the 4 × 100 m relay.