Introduction. Lupus patients have an increased risk of developing infections due to the disease, use of immunosuppressants and corticosteroids. Objective. To identify the associated factors for serious infections in lupus patients in a national referral hospital. Retrospective, analytical, case-control study in the Rheumatology Service of the Guillermo Almenara Irigoyen National Hospital, Lima, Peru. Methods. The registry of hospitalized patients in the study period was analyzed, the cases were patients in whom the etiology of the first infection developed their hospitalization. Controls were hospitalized lupus patients without infections in the same study period. Variables predisposing to the development of infections were analyzed. Results. 61 patients out of 390 hospitalized developed infections during their hospitalization. 48 developed 1 only infectious event (in 40 an etiology deve...