Theory and practice of sport psychology suggest that emotional and behavioral states of anxiety and aggression both affect athletic performance. The aim of the present study was the investigation of possible differentiation among water -polo male and female players according to their anxiety, anger and aggression levels. The sample consisted of 225 players (120 men, 105 women), between the ages of 17–39 years old. They completed the Greek versions of the: (a) CSAI -2, and (b) CAAS instruments. Results revealed differences among almost all questionnaire variables, between sport (athletic) experience’ groups. Finally, male athletes of the 2nd national division identified greater levels of anger and aggression in comparison to all other division groups. Overall, results shine some light on facets that play an important role and can affect the athletic performance of water -polo players.