The association between lymphoproliferate malignancies, especially lymphoma, and rheumatoid arthritis (RA) has been confirmed by several studies. However; there are few reports of RA patients who developed B-cell chronic lymphocytic leukemia (B-CLL) and vice versa. We report a patient with B-CLL who developed RA and another with RA who presented with B-CLL during follow-up. We discuss the incidence of B-CLL among the RA population and the possible interaction of the pathogenetic mechanisms of these two entities.