Introduction. Systemic lupus erythematosus (SLE) is an autoimmune disease that includes a broad spectrum of mucocutaneous manifestations. Objectives. To characterize the clinical spectrum of oral mucosal lesions in patients with SLE and to analize their association with clinical and laboratory parameters. Methods. We performed a cross-sectional study with systematic oral evaluations in SLE adult patients. Systemic and cutaneous lupus activities were recorded. We collected epidemiologic, clinical, and laboratory data. Statistical analysis included the kappa coefficient, X2 test, Fisher’s exact test and Mann-Whitney U-test, adjusting for multiple comparisons according to Bonferroni’s method. Results. A total of 181 patients (92.8% females) were included, with a median age of 37 (range 16-76) years. Cutaneous, systemic, and oral manifestations of lupus erythematosus (LE) activity were found in 31.5%, 23.8% and 18.8% of patients, respectively. Higher titres of anti-double-stranded (ds) DNA antibodies were detected in patients with LE-related oral lesions (LEOL) when compared to those without LEOL [356 (82-1083) UI vs 45 (0-417) UI; p=0.02). LEOL did not correlate to cutaneous (k=0.380) nor systemic (k=0.228) LE-activity (p<0.01). Conclusions. Oral manifestations related to SLE were significantly associated to anti double-ds DNA antibodies. LEOL were independent of cutaneous and systemic activity.