Background: With aging, the facial folds, grooves, and sagging tissue become more prominent. It is haracterized by loss of the collagen mass in the dermis and an increased array of elastin whirls in the deeper dermis. The aim of this study was to determine whether correction of nasolabial folds could be achieved using an allogeneic collagen product. Methods: Nine healthy volunteers participated in this beforeafter, pilot clinical trial. Human allogeneic collagen (Collagel, Kimia Teb Rahavard Co., Tehran, Iran) was injected in both nasolabial folds of the volunteers. Skin hydration was measured using the Corneometer® 580 device (CK GmbH, Cologne, Germany). Ultrasonic dermal changes were measured using an ultrasonography device (22 MHz, TPM, Germany) before and 24 weeks after the injection. One independent investigator assessed the efficacy using standardized photographs before and 24 weeks after injections. The patients’ satisfaction rate was also evaluated.Results: All patients showed improvement in wrinkles and the mean satisfaction rate on a 0-10 VAS was 7.4±0.5. The hydration of the stratum corneum increased from 32.32±13.54 to 52.61±12.55 and the echo-density of the dermis increased from 8.05±3.18 to 9.55±3.36 μm 24 weeks after the injection (P≤0.05). No treatmentrelated adverse events were reported.Conclusion: Collagel is an effective filler that can provide a safe and effective correction of the nasolabial folds. This correction lasts for at least 24 weeks on ultrasound evaluations. Further larger blind-randomized controlled clinical trials are required to pave the way for suggesting it as a possible therapeutic option.