Walter Casadei was born in Forli, Italy. He arrived in Argentina in 1948, and began to work in the Argentine Navy for several years. He began drawing cartoons and jokes, mainly with female characters, for magazines like Loco Lindo, Dinamita, Bomba H, Ricuritas amd Pobre Diablo in the mid-1950s. He was active in "serious comics" from 1957, starting with a collaboration with the magazine Trinchera, for which he illustrated the series 'Rudy Valiente', 'Resignación' and 'Kidor, el Señor del Universo'.
His professional career really took off when he joined the publishing house Columba. There, he published in D'Artagnan, Intervalo and El Tony, for which he created 'Star Kenton' with texts by Hector German Oesterheld in 1958. A year later, he took on 'Torpedos Humanos' in Corso Pete, a series that was previously drawn by Carlos Clemen in Trinchera. Since the mid-1960s, it was difficult to find a job in Argentine magazines, so Casadei went on to draw horror stories for American comic books in the 1970s. After several years of health problems, Walter Casadei died in 1978.