A large part of the world’s population suffers from Striae distensae (SD) or stretch marks, which create physical and psychological discomfort in people. We evaluate the SD clinical improvement by using a non-ablative fractional Nd:YAP 1340 nm laser. The research was performed on 25 patients of both sexes, with a mean age of 31 ± 13.09 years. Each patient underwent from a minimum of 3 to a maximum of 4 treatments, with an Nd:YAP (1340 nm) medical device, every four weeks, with 3- and 6-month follow-up, in these areas: back, abdomen, breast, flanks, lower limbs, buttocks, and thighs. Manchester Scar Scale assessed stretch marks improvement. Side effects, patient pain, and SD overall appearance improvement were also recorded for all patients. Digital photographs measured the aesthetic results. Treatment was well-tolerated (pain score 1.08 ± 0.76) by all patients. There were no long-term side effects, and 88% of patients revealed an SD excellent improvement showing good aesthetic results achieved by the treatment. The total mean pretreatment Manchester Scar Scale score decreased from 13.80 (±1.58) to 10.36 (±1.70) after 3 months (p < 0.01) and to 8.36 (±1.07) after 6 months (p < 0.01). An Nd:YAP (1340 nm) laser seems to be a safe and effective treatment, showing a higher security profile with no side effects.