As a result of increasing life expectancy of lupus patients, malignant disorders have become major determinants of morbidity and mortality. The objectives of this study were to analyze cancer-associated morbidity and mortality, the type of malignancies in Hungarian lupus patients, and to analyze association with immune-suppressive therapy, disease duration, and age of the patients. Data from 860 systemic lupus erythematosus (SLE) patients were retrospectively analyzed in a study period between 1970 and 2004. Results were compared to data from age- and sex-matched population obtained from the Health for All database, and also to literature data. A total of 37 patients presented with cancer, reflecting 4.3% cancer-associated morbidity. Patients were 47 (20-73) years old at the onset of malignancy, which appeared 13 (1-45) years later than SLE. Cancer prevalence was the highest in the first 5-10 years of lupus. Breast cancer was the most common malignancy (n = 11) followed by gastrointestinal tumors (n = 9), cervix cancer and hematologic malignancies (n = 5 for both), bronchial cancer (n = 4), bladder, skin, and ovarian cancer (n = 1 for each). Standardized incidence ratio was the highest for non-Hodgkin lymphoma (standardized incidence ratio [SIR] 3.5, 95% CI 0.4-12.5) and cervix cancer (SIR 1.7, 95% CI 0.6-4.1). Although 76% of patients with cancer received immune-suppressive therapy besides corticosteroids, no direct correlation could be confirmed between therapy and malignancy. Out of the 164 patients that expired during the study period, 18 were cancer-related. As such the cancer-associated mortality was 11% (18/164). This peaked during the last 4 years of the study period (8/24, 33%). Lupus patients are at high risk for particular types of malignant disorders, highlighting the importance of screening measures and focused patient examination.