The 2005 Ballon d'Or winner had spent time in jail along with his brother after being arrested on 6 March, accused of using fake passports.
The pair had previously been denied bail but posted $800,000 (£648,000) each and must now stay in a four-star hotel in Asuncion while awaiting trial.
Both Ronaldinho, 40, and his brother Roberto Assis deny any wrongdoing.
Their lawyer has called their imprisonment "arbitrary, abusive and illegal."
