The relationship between morality and perceptual defense mechanisms was studied. Three new scales were constructed to measure different aspects of morality: moralism (the tendency to evaluate everything in terms of right and wrong), conscience (strength of feelings of right and wrong) and reparation (inclination to repair the damage one has caused). Perceptual defense mechanisms were measured with Kragh’s Defense Mechanism Test (DMT). Three hypotheses about relationships between morality and defense mechanisms, derived from psychoanalytical literature, were tested on 54 male University students. Results show positive correlations between the defense mechanism isolation of affect and moralism, and between identification with the aggressor and reparation. Total amount of perceptual defense correlated positively with moralism. It is argued that the psychological study of morality should take unconscious processes into consideration.