BACKGROUND: Leg ulcers are a poorly known and underestimated complication of sickle cell disease (SCD), but in our experience they often appear as a severely disabling condition, associated with the most severe forms of the disease. OBJECTIVES: To assess the characteristics, complications, repercussion on quality of life and associations of SCD ulcers. METHODS: Case series of 20 patients followed in a French referral centre for SCD and who had previous/present leg ulcers. RESULTS: Median ulcerated area was 12 cm2 and median time spent with ulcers was 29.5 months. Locoregional infections developed in 85%, ankle stiffness in 50% and mood disorders in 85%. Ninety per cent of patients needed analgesics, 20% being opioids. Median loss of time from work was 12.5 months. The Short Form 36 Health Survey showed physical and mental component summary scores of 41.5 and 40.7, respectively, indicating severe alteration close to that found in lung cancer or haemodialysis. Two categories of SCD leg ulcers were distinguished, defined by a 1-year duration cut off. The 'prolonged' ulcers had larger surfaces, tended to recur more frequently and led to more infection and depression. Several SCD complications were associated with leg ulcers, notably priapism, pulmonary hypertension, stroke and acute chest syndrome. CONCLUSIONS: Leg ulcers are a major complication of SCD, given their severe consequences and frequent association with other specific organ damage, and they constitute in their 'prolonged' form a severely disabling condition that remains an important therapeutic challenge.