Striae distensae are dermal atrophic scars with epidermal thinning and decreased collagen and elastic fiber. There is no 'gold standard' treatment modality in the treatment of striae distensae. Collagen is a major extracellular matrix component and is important in wound healing. The ablative CO(2) fractional laser is effective in various cutaneous scars and this study was attempted to evaluate the effect of succinylated atelocollagen and ablative CO(2) fractional laser in the treatment of striae distensae. Participants were divided into two groups and received three laser treatments at a 4-week interval. Clinical improvement was evaluated by participants and two blinded physicians by observing the comparative photographs. Skin biopsies were randomly taken from six participants. The ablative fractional resurfacing laser was effective in the clinical improvement of striae distensae. Statistically significant differences were partly observed between the collagen and placebo groups. Clinical improvement scored by doctors showed more improvement in the collagen group. However, scoring by participants did not show significant differences between the collagen and placebo groups. In conclusion, the ablative fractional resurfacing laser is effective in the treatment of striae distensae and succinylated atelocollagen may also be effective for striae distensae treatment. However, to prove the effect of succinylated atelocollagen, further research with a larger group of participants is needed.