José Antonio Muñoz studied at the Pan-American School of Art, where he attended classes by Hugo Pratt and Alberto Breccia. He became the assistant of Francisco Solano Lòpez and cooperated with Hector Germàn Oesterheld at age 18. He published in magazines such as Hora Cero and Frontera Extra. He drew several episodes of Hugo Pratt's 'Ernie Pike' series and he illustrated 'Precinto 56' from scripts by Ray Collins in the magazine Misterix. He also cooperated with the British Almagamated Press, through the studios of Solano Lopez. He left Argentina in the early 1970s.
He settled in Europe, and began a collaboration with the scenario writer Carlos Sampayo in Spain. In 1975, they began the series 'Alack Sinner', that appeared in the Italian magazine Linus and in the French magazine Charlie Mensuel. Three years later, they launched 'Sophie Goin' South' in B.D. Starting in 1979, he drew for the magazine À Suivre, where he continued 'Alack Sinner' and created 'Le Bar à Joe' ('Joe's Bar'), 'Histoires Amicales du Bar à Joe', 'Sudor Sudaca', 'Billie Holiday' and 'Trains sur l'Eau', among others. Most of these stories were collected in albums by Futuropolis and Casterman.