Although osteonecrosis (ON) is a well-known complication of systemic lupus erythematosus (SLE), the diagnosis is generally delayed. Steroid treatment is considered the major risk factor for the development of ON in SLE. ON involving at least tree anatomical localizations is called multifocal osteonecrosis (MFON). We presented a case with MFON diagnosed with SLE seven years ago. The patient has received corticosteroids at various doses and had obvious destruction in the shoulders and hips apparent in plain X-rays. Although the knees seemed normal in X-rays, scintigraphy and magnetic resonance imaging (MRI) revealed ON of the knees. SLE patients with ON in one joint should be screened with MRG and/or scintigraphy in the early stages of the disease even when the plain X-rays seem normaldue to the increased risk of multifocal ON involving other joints.