100 mg/L in 90.6%. Gram positive cocci were the most frequently isolated microorganisms (81.5%), predominating S. aureus (48.1%), and with 4 isolates methicillin resistant isolates (26.7%). Resistant isolates trend to be associated with previous surgery (p = 0.055) and all cases caused by non-fermentative Gram negative bacilli had recent hospitalization or surgery, a feature that did not reach a significant difference. Nine events were associated to bacteremia (36%). Outcome analysis indicated 32% of events with full recovery, 28% with a favorable evolution, 20% with therapy failure and 16.7% patients that died. A total of 24% of the series remained with significant sequels. Conclusions: Septic arthritis is an infrequent disease that affects in most cases patients with predisposing conditions. Associated symptoms include pain and impaired joint movement, sometimes fever, hypotension, positive blood cultures and frequently a C-reactive protein > 100 mg/L. Predominant agents are Gram positive cocci, specially S. aureus, including methicillin resistant isolates. Case-fatality ratio, treatment failure and sequels are important.]]>