His single "Here In My Heart" was number one in the first UK Singles Chart, published by the New Musical Express in 1952, putting him into the Guinness Book of World Records. The song also stayed there for 9 weeks

One of the most successful Martino hits was "Spanish Eyes", achieving several gold and platinum awards for sales. In 1965, the song reached number 15 on the UK singles chart. Even today, this classic by the late composer, Bert Kaempfert, is among the 50 most-played songs worldwide. Another smash hit was the mega-seller, "Volare" (also known as "Nel blu, dipinto di blu"). In 1976, it reached number one on the Italian and Belgium charts, and was in the Top Ten in Spain, Holland and France, as well as in many other European countries. In the U.S., Martino had eleven top 40 hits in the Billboard pop singles chart in the 1960s and 1970s, with 1963's "I Love You Because" and 1964's "I Love You More and More Every Day" both reaching the top ten.

Apart from singing, Martino has acted in a number of movies, notably, he played the role of Johnny Fontane in the 1972 film The Godfather, as well as singing the film's title score, "The Love Theme From The Godfather". He played the same role in The Godfather Part III (1990) and The Godfather Trilogy: 1901-1980 (video, 1992). He recently returned to acting, playing aging crooner Sal Stevens in the short film Cutout, appearing in film festivals around the world in 2006.