Hypertrophic scars are fibroproliferative diseases of the skin. Many treatment options are now available, but none is completely effective. The primary objective ofthis study was to compare the efficacy of a betamethasone valerate (BMV) 2.25 mg plaster versus no treatment in the prevention of hypertrophic scars after anterior trunk plastic surgery. An exploratory, open, prospective, controlled study was carried out on 16 consecutive patients with postoperative wounds. A 12-week daily treatment was initiated after wounds cicatrisation. The effect of a daily application of the plaster was compared to no treatment by dividing the wound into 2-4 parts. The wound evaluation was performed during the treatment period at 2, 4, 8 and 12 weeks, and 6 months after the end of the treatment. A total of 60 wounds was evaluated. Pain and itching improved in both groups after 12 weeks. However, only the wounds treated with BMV plaster showed a significantly greater and more rapid improvement as compared with the non-treated wounds after 4 and 8 weeks of treatment in all the evaluated parameters (p<0.0001). The efficacy and tolerability of BMV plaster in the prevention of hypertrophic scar development is promising.