Abstract Spontaneous bacterial peritonitis (SBP) is a frequent and severe complication that occurs in patient with cirrhosis and ascites. It occurs in 10% to 30% of patients admitted to hospital. The organisms that cause SBP are predominantly enteric. Escherichia coli is the most frequent recovered pathogen, and Gram-positive bacteria, mainly Staphylococcus spp., are being considered an emerging causative agent of SBP. Streptococcus bovis that may be found as part of the commensal bowel flora in about 10% of healthy adults constitute an uncommon cause of peritonitis that was first reported in 1994. We describe the first case of SBP at the University Hospital of Santa Maria (HUSM) caused by S. bovis, resistant to the antibiotics erythromycin and clindamycin (inducible clindamycin resistance detected by disk diffusion test using the D-zone test).