In order to investigate the relationships between psychopathology and aggressive behaviour on the one hand and cancer pain perception on the other, 11 patients who suffered from neoplasm were investigated by means of Symptomatology Check List (SCL-90) by Derogatis, Inventory for assessing different kinds of hostility (QTA) by Buss-Durkee, Scala di Autovalutazione per la Depressione (SAD) by Cassano & Castrogiovanni and Mc-Gill Pain Questionnaire (MPQ.) by Melzack. The results show that when psychopathologic symptoms are present, they lead the patient to feel pain as unbearable, thus arousing violently homicidal thoughts. Features of aggressivity once experienced, lead to an almost personified and extremely active image of pain.