The relativistic ethical position rejects the possibility of relying on universal moral norms to draw conclusions from moral judgments. It can influence moral behavior, particulary in prosociality and penalization of faults and crimes; empathy has an important mediating role. The objective of the present paper was to test an interaction of variables model (using SEM), being relativism and moral absolutism predictor variables, empathy variable mediator and prosocial behavior and penalization of faults and crimes dependent variables. The variables were measured in a sample of 515 adolescents between 17 and 20 years of age, with a mean age of 17.49 (SD = 72); 166 males and 349 females, belonging to the province of Entre Rios and Buenos Aires, Argentina. The results indicated a good fit between the proposed model and the empirical data. It was obtained an X-2(1) = 2.55, p = .11, X-2(2), gl = 2.55. The following adjustment indexes were also obtained: GFI = .99, AGFI = .97, CFI = .99. Absolutism as a predictor variable had a positive effect on the penalization of crimes and faults. This positive effect was increased by empathy as a mediating variable between both variables. Relativism had a negative effect on the penalization of faults and crimes. The results of the proposed theoretical model confirm the importance of relativism and moral absolutism on the penalization of faults and crimes, and prosocial behavior; with an important mediating role of empathy for the concretion of the moral.