Osteoid osteoma is infrequently encountered in the carpal bones. Its typical radiological features are not usually observed in this localization, which may result in delayed diagnosis. Since incomplete removal of the nidus may result in persistance or recurrence of the symptoms, other methods of locating the tumour during the resection should be used. We report a case of an osteoid osteoma of the triquetrum which, after incomplete initial resection and several revisions, developed instability of the carpus which required a limited intracarpal arthrodesis. A screw fragment left after implant extraction limited the imaging possibilities to study the persistent nidus. Intra-operative localization of the nidus with tetracycline dye and its visualization with ultraviolet light facilitated the complete removal.