12 patients with pain in the piso-triquetral region are described. 11 had radiological evidence of osteoarthritis of the piso-triquetral joint, which was confirmed in the nine cases treated by excision of the pisiform. Seven of these had complete relief of symptoms. The clinical findings are constant and relief of pain by conservative treatment is usually only temporary. Ulnar nerve symptoms were present in four patients and these were also relieved by surgery. Excision of the pisiform is a useful operation for this condition, which often remains undiagnosed due to incomplete clinical and radiological evaluation. Full return to normal function is the rule if the problem is not associated with other wrist pathology.