New acetamidines structurally related to N-(3-(aminomethyl)benzyl)acetamidine (1, W1400) were designed as inhibitors of inducible nitric oxide synthase (iNOS). Six compounds were found to be selective for iNOS over endothelial nitric oxide synthase (eNOS), and among them, the most active and selective compound was the N-benzylacetamidine 2. A docking study was also performed to shed light on the effects of the structural modifications on the interaction of the designed inhibitors with the NOS.