The aim of this study was to investigate whether there is any significant bone loss of the ulna and radius following acute tendon-artery-nerve clean-cut injuries at the wrist level which were repaired and rehabilitated by early passive mobilisation. Fifty-eight patients who underwent such operation were enrolled in this study. Patients in Group I (n = 28) had primary tendon repairs alone, in Group II (n = 15) primary tendon and nerve repairs and in Group III (n = 15) primary tendon, nerve and artery repairs. Bone mineral density (BMD) measurements of the ulna and radius were obtained during the first week, the sixth week, the third month and the 12th month after operation. The results demonstrated that BMD decrease in the ulna was more common than in the radius. When compared with the first week BMD measurements, the highest reduction was seen in the sixth week in Group I and during the third month, when bone loss of both the radius and ulna was considerable in Group II. The bone loss in all groups and subgroups were found to have recovered at the 12th month measurements, except in the distal region of the ulna in Group I. This study suggests that passive immobilisation is deleterious in respect of demineralisation of the forearm bones.