Pustulotic arthroosteitis is a relatively common disease in Japan, but coexistence of rheumatoid arthritis (RA) and pustulosis palmoplantaris (PPP) is uncommon. The case report of a 38-year-old woman illustrates a rare and poorly understood relationship between PPP and RA. The two diseases have in common a tendency of leukocyte migration, which is the basis of a hypothesis of a related cause.