This study investigated whether validation intervention, which conveys to a client that what they are experiencing is valid and understandable given their context, is effective in reducing the shame, anger, and aggression in individuals with narcissistic traits. Sixty-nine participants took a manipulated geometric reasoning test and received negative feedback on their performance. After that, they were randomly assigned to the validation or control group and listened to a recorded voice as an intervention. Shame and anger were measured before and after the intervention; in addition, baseline and post aggression were measured by the CRT game. Compared to the control group, the validation group reported lower levels of shame, anger, and aggression after the intervention. Implications for counseling using validation as an intervention and possible future research are discussed.