The aim of this study was to evaluate the joint count for affected joints and involvement distribution in erosive osteoarthritis (EOA) versus nodal osteoarthritis (NOA) of the hands in patients matched for sex, age, and disease duration. After recruitment of 101 consecutive outpatients affected with EOA, 101 patients affected by NOA were selected and matched for age, sex, and disease duration. Joint count for distal interphalangeal (DIP), proximal interphalangeal (PIP), and first carpo-metacarpal (CMC-1) joints, presenting Kellgren and Lawrence grade 2-4 OA, was performed. In our study, the number of affected joints was higher in NOA, with significant differences for some articular districts, especially in PIP joints of the fourth finger, and DIP joints of the second, third and fourth fingers.