OBJECTIVE The purpose of this study was to compare the effects of ticlopidine and clopidogrel on the development of neointimal hyperplasia after experimental arterial injury. METHODS This experimental, prospective, randomized controlled study was performed on twenty-seven rabbits, which were divided into three groups, each of which contained nine subjects. Following the development of a balloon catheter injury in the iliac artery, no drugs were administered to Group 1 (control). Group 2 was given ticlopidine, while Group 3 was given clopidogrel. At the end of the 21-day experimental period, arterial sections were evaluated histomorphologically and immunohistochemically with staining using antibodies against platelet derived growth factor beta and basic fibroblast growth factor. Statistical analyses were performed using Chi-Square, Mann Whitney U and one-way ANOVA tests. RESULTS At the end of study period, ticlopidine and clopidogrel strongly reduced the development of intimal hyperplasia after arterial injury (54.1%, p<0.001, 53.2%, p<0.001, respectively). No significant difference was observed in terms of intimal and medial areas between the drug-treated groups. Expressions of the basic fibroblast growth factor and platelet derived growth factor beta were significantly lower in the intima of drug treated groups with respect to the control group (p<0.05). CONCLUSIONS The results of our study suggest that ticlopidine and clopidogrel, which are widely used in antiplatelet treatment in clinics, can similarly prevent the development of intimal hyperplasia after experimental arterial injury.