Don Osvaldo is an Argentine rock band formed in November 2010, when Patricio Santos Fontanet changed the name of Callejeros, after their official separation on November 12.

The band was first called Casi Justicia Social. However, on September 29, 2014, the group announced its new name one in homage to Osvaldo Pugliese.

The new band debuted in the Club Banda Norte de Río Cuarto, Córdoba. Interpreting Callejeros songs, while adding four new songs.

Late in 2010, after the dissolution of Callejeros due to internal problems caused by the events happened in República Cromagnon and subsequent problems to justice and the victim's families, Patricio Santos Fontanet announced the formation of Casi Justicia Social with some ex-members. The new band kept CJS's initials, that sometimes identified Callejeros.

CJS played concerts throughout Argentina, playing songs from Callejeros and Casi Justicia Social's own songs like "O no", "Suerte", "Acordate" and "Tanto de todo".

Late in May 2012, after suspending shows programmed by June and July, they announced the pre-production of a studio album.

• casijusticiasocial.com.ar, official web site integrated by Pato and Dios, bass player. (Spanish)
• El País: Se desarmó el grupo Callejeros (Spanish)
• Se disolvió el grupo “Callejeros” (Spanish)