摘要： Background: Solar lentigines are skin lesions manifested by benign dark pigmentation causing a cosmetic problem in many patients. Several treatment modalities used for the management of solar lentigines. Side effects and rates of recurrence may be associated with them. Objective: Treating solar lentigines with two different techniques of pulsed dye laser and evaluation of the results both clinically and via the examination of ultrastructural changes by electron microscopy. Patients and methods: This study was conducted on twenty-two subjects with solar lentigines and having Fitzpatrick III-IV skin types, was managed by the use of pulsed dye laser after enrolling them into two groups. Group I (one stacked pulsed dye laser was used) and Group II (treated by stacked pulsed dye laser in two sessions, one month apart). At baseline and six months after treatment, two punch biopsies with a diameter of 2mm were taken from all patients. All taken biopsies were prepared for light and electron microscopic examinations. Results: Both pulsed dye laser techniques induced significant better clinical and histological outcomes. No one demonstrated any postoperative complications such as post-inflammatory hyperpigmentation and scarring. Conclusion: The two techniques of pulsed dye laser are efficient for solar lentigines treatment.