Striae distensae (SD), commonly known as stretch marks, represent linear dermal scars associated with epidermal atrophy. It is prevalent in all races. Objective: The aim of this study was to compare the efficacy and the safety of use of ablative fractional CO2 laser therapy and carbon dioxide gas intradermal injection in treatment of striae distensae. Methods: The present study included 20 patients diagnosed with striae distensae who had never received any previous treatment for SD. There were three groups; each group composed of 10 patients: The first group was treated with ablative fractional CO2 laser resurfacing 10,600 nm The treatment parameters in this study were: energy (30-40 mJ), pulse duration (1.4-1.8 ms), scanning area (20 mm x 5 mm), depth level (1-2) and density level (8-16) according to each patient condition and skin type. Stria of the second group was treated with intradermal injection of carbon dioxide gas. 4-mm bunch biopsies were taken from patients before and after treatment by and results showed high percentage of excellent improvement with fractional CO2 laser.Results: Carbon dioxide laser showed significant higher percentage of excellent improvement after last session of treatment of SD, when compared with carbon dioxide injection.Conclusion: Treatment with CO2 laser showed significant higher frequency of striae with excellent improvement, with good improvement, when compared to treatment with CO2 injection (carboxytherapy). Fractional CO2 laser is promising tool in dermatology and in treatment of SD (safe and effective).