The application of laser as a monotherapy has been shown to reduce probing pocket depths and increase clinical attachment levels after treatment of patients suffering from chronic periodontitis. Its controversial use as an adjunct to scaling and root planing (SRP) is discussed. The present study aimed to evaluate the efficacy of adjunctive Er, Cr:YSGG laser application following conventional SRP. A total of 30 patients with chronic periodontitis were enrolled in the study. The quadrants of each patient were allocated to either SRP or SRP + laser. A total of 3,654 sites with pocket depths ≥ 4 mm were treated and evaluated at 6 weeks and 6 months postoperatively with respect to attachment gain. Both therapies resulted in improved probing pocket depths and clinical attachment levels. The adjunctive application of Er, Cr:YSGG laser following SRP did not improve probing pocket depth or attachment level compared with SRP alone.