The first applications of laser in surgery of the locomotor apparatus in the early 1980s used the haemostatic properties of laser to diminish the amount of substitution of coagulation factors in haemophiliac patients. Only since the early 1990s has a device been available in corporating the pulsed holmium:YAG laser which works in a fluid medium without relevant side effects. Apart from haemostasis, the cutting function and tissue ablation, together with the thermal shrinking effect, are exploited in arthroscopy and percutaneous disc decompression. Now that the biophysical mechanisms of action have been elucidated, nothing stands in the way of the use of infrared lasers in open surgery of the locomotor apparatus in some indications. In a prospective clinical study we included 30 consecutive patients who underwent open laser surgery from November 1992 to August 1994, for the following indications: the sparing haemostatic tissue ablation was used for synovectomy or for bony resection in osteophytes and osteochondromas of different locations, an osteoid osteoma and a painful sacral hyperplasia in the presence of incomplete sacral meningomyelocele. With bleeding eliminated, the shaping was much easier. The non-ablative shrinking produced less tissue loss and a stabilizing strengthening of tissue at the margins of soft tissue resections, e.g. in jumper's knee, tennis elbow and Achilles tendon cysts. All laser functions that are useful in open surgery have also been used in sequestered disc herniations that are inaccessible a percutaneous procedure and, in spinal decompression, for remodelling of the posterior spine contour. An analgesic effect of laser limited the postoperative administration of analgesic drugs to an average of 3 days. No complications related to the laser treatment were observed. At follow-up 12-21 months after operation, 25 of the 30 patients in this heterogeneous population showed complete or near-total healing of the operated pathological finding, and a further 3 patients showed significant improvement. To what extent these very encouraging results will persist will be shown by long-term observation.