We retrospectively reviewed the results of decompression of the flexor carpi radialis tunnel in ten patients (six women and four men) who had tendinitis. The average age of the patients at the time of the operation was forty-five years (range, twenty-five to fifty-eight years). The average duration of follow-up was forty-four months (range, twenty-eight to seventy-six months). The primary symptom was pain, localized to the proximal aspect of the trapezium, that was accentuated by resisted flexion of the wrist and radial deviation. The diagnosis was confirmed in five patients when Xylocaine (lidocaine), injected into the area of the tenderness, decreased the pain. Two patients had evidence of idiopathic tendinitis, which one patient believed to be associated with activities involving repetitive flexion of the wrist. The tendinitis developed after fracture of the scaphoid in two patients, fracture of the distal aspect of the radius in one, excision of a ganglion in two, carpometacarpal arthrodesis in one, and blunt trauma in two. The mean duration of symptoms before the operative intervention was sixteen months (range, one to forty-three months). The intraoperative findings included adhesions in six patients, attrition or rupture of a tendon in four, exostosis in three, stenosis in three, and an anomalous tendon in one patient. Additional procedures, such as excision of a ganglion, removal of an exostosis, tendon transfer, or application of a fat graft, were performed in seven patients. Nine of the ten patients had relief of the symptoms and were able to resume their preoperative employment and leisure activities. One patient continued to be symptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)