Vasquez based Fernando aka Vinny on himself. According to Vasquez, he went through a phase of wearing his hair slick back. His friends accused him of trying to look Italian and nicknamed him "Vinny". He also said that Vinny's womanizing was based on himself. Vinny originally had many more lines in the film because Vasquez originally wrote the part for himself. But he trimmed the part in editing so the character would not overshadowed the rest of the cast.
John Leguizamo originally wanted to play Johnny as being street-smart and wearing the latest urban fashion. But Vasquez insisted that Johnny be an innocent character. Leguizamo originally could not believe that a young man from the ghetto could be so innocent until Vasquez revealed that that part of Johnny was based on himself.