The aim of this study was to determine the analgesic, anti-inflammatory and healing effects of soft-laser treatment in a double-blind crossover study of periodontal post-surgical patients. For each patient, mucogingival procedures were required on contralateral sides of the mouth for similar problems. Twenty-eight patients had a total of 28 pairs of surgical procedures performed. Prior to surgery, a complete examination was carried out, scaling and root planing were performed, and oral hygiene instructions were given. Following surgery on both sides of the mouth, one site was lased and a placebo procedure was carried out on the other site. The patients evaluated pain three times a day for one week (modified McGill pain scale). An inflammatory index (Loe and Silness Index) was ascertained at days 7 and 14 for both sides of the mouth. A healing score (Landry, Turnbull, Howley Index) was evaluated at days 7 and 14. For both surgical procedures, the assessments were carried out in the same manner. Univariate and multivariate analyses of variance were performed for all parameters. The results showed no significant differences in the gingival index, healing index and pain reduction when the soft laser treatment was compared to the placebo operation. These results suggest that soft laser (As-Ga and He-Ne) treatments may not be a useful adjunct after certain periodontal surgical procedures.