Background:. Stretch marks can have a negative psychological impact on some individuals. Methods are available for treating stretch marks, but high-quality evidence supporting their use is limited. We treat stretch marks using injections of diluted calcium hydroxylapatite (CaHA, Radiesse) filler combined with microneedling and topical ascorbic acid. This retrospective study evaluated the effectiveness of this combined therapy. Methods:. Subjects presented with red (n = 25) or white (n = 10) striae on their buttocks, thighs, knees, abdomen, and breasts. CaHA filler was diluted 1:1 with lidocaine 2% without epinephrine. A maximum of 3.0 mL of filler was injected per patient at all skin depths using a 23G needle. This was immediately followed by microneedling and topical application of 20% ascorbic acid. Microneedling with ascorbic acid was repeated after 1 and 2 months. Skin biopsies were obtained from a patient who later underwent abdominoplasty. Results:. The mean (±SD) pretreatment Manchester Scar Scale scores were 12.0 (±0.8), decreasing to 7.1 (±1.4) 1 month after the final treatment, indicating improvement in stretch mark appearance (P < 0.001). Subjects were very satisfied (n = 22; 62.9%), satisfied (n = 8; 22.9%), neither satisfied nor dissatisfied (n = 4; 11.4%), or unsatisfied (n = 1; 2.8%) with their treatment results. Analysis revealed a significant correlation between Scar Scale scores and Patient Satisfaction scores (r = 0.483; P = 0.003). Skin biopsies showed increased quantity and quality of collagen and elastin fibers in areas treated with combination therapy. Procedures were well tolerated. Conclusion:. Combining 1:1 diluted CaHA with microneedling and topical ascorbic is safe and effective for treating stretch marks.