This work describes the development of sideroblastic anemia (SA) during the clinical activity of systemic lupus erythematosus (SLE) in two patients. The cases refer to two women with SLE who developed SA during a relapse of the illness. Both patients fulfilled at least four criteria of the American Association of Rheumatology for SLE. In one patient, the treatment with prednisone was followed by the resolution of the SLE activity and the disappearance of the SA. Several years later there was no evidence of ringed sideroblasts or malignancy in the bone marrow. In the other patient, the clinical activity of the SLE and SA developed during the beginning of a septicemic event which finally led to her death. Our clinical cases allow us to show that the transitory development of SA can occur during a period of clinical activity of SLE and that its association, although infrequent, is due to a common physiopathogenic mechanism.