Three cases of sternocostoclavicular hyperostosis (SCCHO) or pustulotic arthro-osteitis (PAO) associated with plantar pustulosis are presented. Two of them were associated with psoriasis vulgaris although the pustulosis was of a different histological type in each case. Anatomo-pathological study of two of these three cases shows that this hyperostosis is secondary to an inflammatory osteomedulloperiosteal remodelling suggesting an infectious origin which remains to be proven. The relationship of this syndrome with some seronegative spondylarthropathies cannot, however, be excluded.