Objective: The advent of dental lasers has raised another possible treatment option for dentine hypersensitivity (DH) and has become a research interest in the last decades. The aim of this randomized, controlled, double-blind, split mouth, clinical study was to evaluate and compare the desensitizing effects of erbium, chromium-doped:yttrium, scandium, gallium and garnet (Er,Cr:YSGG) to galium-aluminium-arsenide (GaAlAs) laser on DH. Methods: Fifty-one patients participated in this study for a total of 174 teeth. DH was assessed for all groups with a visual analog scale. For each patient, the teeth were randomized to three groups. In the diode laser group, sensitive teeth were irradiated with the GaAlAs laser at 8.5J/cm(2) energy density. In the Er,Cr:YSGG laser group, sensitive teeth were irradiated with Er,Cr:YSGG laser in the hard tissue mode using a none-contact probe at an energy level of 0.25W and repetition rate of 20Hz, 0% water and 10% air. In the control group no treatment was performed. Treatment time was 60s for GaAlAs laser and 30s for Er,Cr:YSGG laser. Results: When compared with the control group and baseline data, in both laser groups, laser irradiation provided a desensitizing effect immediately after treatment and this effect was maintained throughout the study (p<0.05). No significant differences between Er,Cr:YSGG and GaAlAs laser groups were found at any follow-up examination (p>0.05). Conclusion: Based on these findings, it may be concluded that both Er,Cr: