Jay Ilagan, who had previously acted in Brocka's films, initially played the lead role of Julio Madiaga. Having already participated in several days of shooting, Ilagan was asked to drop out of the production when Brocka became dissatisfied with the performance. Upon viewing the dailies, Brocka was convinced that Ilagan, who had a very healthy appearance, did not meet his vision of Julio—a pitiful vagrant that wades in and around the urban gutters. The role was re-cast with newcomer Bembol Roco in the part. Prior to this film, Roco's only foray in to acting was a relatively small role in Brocka's previous film, "Three, Two, One". For this film, he was credited under his real name of Rafael Roco, Jr. "The Claws of Light" marked what would become the first lead role for Roco.