To date, few cases of hemoglobinopathies in patients with rheumatoid arthritis (RA) have been reported (Marino and Mcdonald in J Rheumatol 17:970-972, 1990; Gladman and Bombardier in Arthritis Rheum 30:1065-1068, 1987; Michel et al. in Semin Arthritis Rheum 38:228-240, 2008). These haemoglobin diseases are associated with characteristics abnormalities of the skeleton. Haemoglobin C disease is a benign hemoglobinopathy rarely associated with skeletal disorders [Piéron et al. in la semaine des hôpitaux 57(1-2):22-25, 1981]. We report a case of RA in a 60-year-old woman with homozygous haemoglobin C disease. This coexistence may be a pure coincidence, although we discuss the difficulties with RA treatment in this case due to the unknown effect of anti-rheumatic drugs on the progression of haemoglobin C disease.