The aim of the present study was to classify pathological gamblers based on their psychopathology as related to the variable sensation-seeking, and to check possible differences between the groups on the sociodemographic variables. The sample was composed of 110 male pathological gamblers using slot machines who requested treatment at the Pathological Gambling Unit at the Ciutat Sanitària i Universitària de Bellvitge. It was observed that pathological gamblers comprise three clusters, differentiated with differing severity depression, psychoticism, somatization, impulsiveness, interpersonal sensitivity, and phobic anxiety. Cluster 1, representing 46.7% of the sample, showed mean scores higher than or equal to T=63. On the sub-scales of Depression, Psychoticism, Interpersonal Sensitivity, Phobic Anxiety, and Obsessiveness-Compulsiveness the score was close to T= 63 (the clinical cut-off score). Cluster 2, representing 23.8% of the sample, scored higher than Cluster 1 on the following subscales: Depression, Phobic Anxiety, Interpersonal Sensitivity, Psychoticism, Obsessive-Compulsive, and Somatization. On Cluster 3 highest mean scores were observed on all SCL-90-R dimensions relative to the other two groups. What distinguished these subgroups is not symptomatology but the severity of the psychopathology. On the other hand, sensation seeking was similar for the three clusters, and the slight differences depended on the subjects' psychopathology.