Objective: The aim of this retrospective study was to investigate the effect of photobiomodulation therapy on postoperative pain provoked by thermal stimulation in direct pulp capping. Subject and methods: A retrospective study was performed using the records of patients who received direct pulp capping using mineral trioxide aggregate. Teeth irradiated with a laser were assigned as the photobiomodulation therapy group and non-irradiated teeth were considered as the control group. Before treatment and 6 hours, 1 day and 7 days after treatment, tooth sensitivity to a cold stimulus was recorded using a visual analog scale. Results: From a total of 123 documented direct pulp capping procedures, only 72 directly capped permanent teeth met the inclusion criteria. Age, gender, and tooth location were comparable between the groups. A statistically significant difference was found in sensitivity to cold stimulus between groups on day 7 (p=.007), but no difference was found at the preoperative, 6 hour, and day 1 time points (p=.055, p=.132, p=.100, respectively). In the intragroup evaluation, a significantly greater decrease was detected in the photobiomodulation therapy group compared to the control group, although both groups showed a reduction in discomfort throughout the follow-up period (p=.000). Conclusion: Photobiomodulation therapy is an effective method for enhancing patient comfort by reducing thermal sensitivity following direct pulp capping procedures.