The aim of this study is to evaluate the prevalence and percentages of personality patterns, and explore their relationship with clinical syndromes in a sample of 212 pathological gamblers from a rehabilitation center. The study also explores the possibility of profiles, common in gamblers, in which personality disorders and clinical syndromes coexist. The Millon Clinical Multiaxial Inventory (MCMIII) was employed. Four clinical personality patterns were the most frequently identified: dependent, obsessive-compulsive, narcissistic and antisocial. The relationship between personality patterns and clinical syndromes was also analyzed. Subsequent cluster analysis revealed two personality profiles, with features belonging to different scales, called "antisocial profile" and "obsessive-compulsive profile". These two profiles differ considerably in their relation to clinical syndromes. The "antisocial" group scores significantly higher on all clinical syndromes, and close to the clinical score in the cases of alcohol abuse, drug abuse, psychotic thinking and delusional disorder.