MMPI-2 validity scales of two groups of parents going through child custody evaluations, parents who engage in parental alienation syndrome (PAS) behaviors and parents who do not, were compared. It was hypothesized that PAS parents would have significantly higher L and K scales and a significantly lower F scale than parents who do not engage in these behaviors. Using female subjects, since few males were available, the hypothesis was confirmed for K and F scales, indicating that PAS parents are more likely to complete MMPI-2 questions in a defensive manner, striving to appear as flawless as possible. It was concluded that parents who engage in alienating behaviors are more likely than other parents to use the psychological defenses of denial and projection, which are associated with this validity scale pattern. Implications of this finding regarding possible personality disorders in PAS parents are discussed.