Systemic lupus erythematosus (SLE) is an autoimmune disease with various oral manifestations, including ulceration, white keratotic plaques, oral discoid lupus erythematosus, oral lichen planus (OLP)-like lesions, non-specific erythema, purpura, petechiae, and cheilitis, which resemble lesions of other systemic diseases. Recognizing the oral manifestation of SLE is essential for comprehensive patient management. This study reports 4 cases of SLE with various oral lesions, underlying conditions and diagnostic methods.In September 2019, 2 adult SLE patients and 2 juvenile SLE patients were consulted at the Oral Medicine Clinic. The assessment of systemic diseases was conducted by the Internal Medicine and Pediatrics resident, whereas the Oral Medicine resident performed the intraoral examinations. The medical history, clinical findings and laboratory results were analyzed to establish the diagnosis.The first patient was a 38-year-old female presenting with multiple white keratotic plaques throughout the mucosa, an OLP-like lesion on the right buccal mucosa, petechiae on the hard palate, and petechiae and purpura on the upper and lower extremities. The second case was a 24-year-old female with a malar rash and multiple ulcerations on the vermilion zone, an OLP-like lesion on the left buccal mucosa, and a palatal ulcer. The third and fourth cases were 16-year-old females with a prominent butterfly rash. The patients presented with acute pseudomembranous candidiasis, an aphthous-like ulcer and keratotic plaques. They received antimicrobial therapy for the intraoral lesions and showed promising results.The oral lesions in adult-and juvenile-onset SLE patients varied depending on the disease severity and treatment received.