Background: Striae distensae are frequent undesirable skin lesions that result in considerable aesthetic concern. Successful treatment has always been challenging and several modalities are available, yet none of them is consistently effective and no single therapy is considered to be pivotal for this problem. Laser has become a popular therapeutic alternative.Aim of work: The present study was designed as an evaluative study of the long pulsed 1.064-nm Nd:YAG laser in treatment of striae distensae using histological and image analysis studies. Methods: Forty female patients with skin types III-V were subjected to 3-4 sessions with 4 weeks interval and a follow up period of a month from the last session. Each patient was subjected to two biopsies; one before treatment and another from the same stria one month after the last session. The biopsies were subjected to histological and morphometric studies of collagen and elastic fibers. Results: The study showed minimal non significant clinical improvement; decrease in erythema in 7 patients with striae rubra and increase tightness of striae in 6 patients (4 alba and 2 rubra). The histological examination showed increase collagen and decrease elastic fibers with reorganization of the fibers after treatment. By the image analyzer there was a significant quantitative increase in collagen fibers and decrease in elastic fibers (P < 0.001 for both collagen and elastic fibers). The side effects observed in the present study were minimal and non significant, mostly pain during session and pigmentary alterations. Conclusion: The present study showed minimal clinical improvement in striae treated, yet the histological improvement was significant with low side effects.