A total of 356 incarcerated male offenders and 501 males from the general population volunteered to participate in the study. The offenders were recruited from a provincial jail in Ontario, Canada, that houses men sentenced to up to 2 years less a day. Men from the general population were recruited in community centers. There were no significant differences between the two groups in terms of age, marital status, and education. The study used a factorially derived model of loneliness and a questionnaire that was developed by Rokach and Brock (1997). The 82-item yes/no questionnaire was composed of five subscales: Emotional Distress, Social Inadequacy and Alienation, Growth and Discovery, Interpersonal Isolation, and Self-Alienation. Participants were asked to reflect on past loneliness experiences and to endorse the questionnaire items that describe those experiences. Results replicated those of Rokach and Koledin (1997) and supported the hypothesis that the experience of loneliness of offenders differs significantly from that of the general population. In the current study, the general population scored significantly higher than the criminals on Social Inadequacy and Alienation and on Growth and Development. 4 tables, appended sample items of subscales and offense categorization, and 34 references