Since septic sacroileitis is one of the less frequent localizations among joint infections, we decided to review 9 cases in a retrospective study of 5 females and 4 males, aged between 22 and 60 years old. None had a clinically predisposing condition. The initiating factor was gynecologic-obstetric in 4 women, the irruption of the skin barrier in 3 cases and finally in one case the infection reached the joint through the psoas muscle. Fever and lumbar pain were present in all cases and allowed diagnostic orientation. Radiologic and centellographic alterations were useful for clinical confirmation. An articular biopsypunction was performed in 4 cases, while in the other 5 cases the clinical and radiologic features and the bacteriologic positivity in the blood cultures were enough criteria for diagnosis. The bacteriologic findings were Staphylococcus aureus (4 cases), Streptococcus group A beta hemolítico (1 case), Staphylococcus coagulase negative (1 case), Streptococcus agalactiae (1 case), Proteus mirabilis (2 cases). Eight out of 9 patients were treated with a B-lactamic and aminoglycoside association. One patient received her treatment per os, with quinolones. Six patients recovered, 2 died and one needed to be sent to another hospital.