OBJECTIVE: Inactivation of poly(ADP-ribose) polymerase 1 (PARP1) has been found to have protective effect in several fibrotic diseases. But the effect is not studied yet in keloids. Herein, we evaluated the therapeutic effect of PARP1 inhibitor, rucaparib, for keloids. METHODS: The protein expressions of PARP1 and smad3 were evaluated with western blotting in keloids and controls. The effect of rucaparib was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and migration assay. We further analyze the effect of rucaparib on patient-derived keloid xenograft murine model. RESULTS: The protein expressions of PARP1 and smad3 were significantly higher in keloid tissue. Rucaparib (20 μM) significantly suppressed the proliferation of keloid fibroblasts. Moreover, the combination of rucaparib (20 μM) and triamcinolone (50 μM) showed additive suppressive effect on keloid fibroblasts. Migration assay showed rucaparib (10 μM) significantly suppressed the migration of keloid fibroblasts. Fibrosis markers in keloid fibroblasts significantly decreased after rucaparib treatment (20 μM). In patient-derived keloid xenograft model, rucaparib significantly reduced the size of keloid tissue. CONCLUSION: The study data suggest that PARP1 might be a novel therapeutic target for keloid disease. Rucaparib might be a promising therapeutic drug for the treatment of keloid disease.