Serum cholesterol fasting concentrations were measured in 274 subjects with personality disorders, who had committed offences. Of these subjects, 139 were found to possess the antisocial personality (sociopathy or psychopathy). With standardized ages, the group of subjects with antisocial personality had a clearly lower mean level of serum cholesterol than the group with other personality disorders which was used as a control group. The use of a mean male population with standardized ages as a control group further emphasized the lovv values of the serum cholesterol of the antisocial personality group.