Objective: To examine demographic and clinical determinants of seeking help for mental or emotional problems. To determine the proportion of those people with a disorder who sought help. To determine what categories of professionals are sought by those who get care. Method: A 2-stage random sample of 3956 adult residents of Edmonton, Alberta, Canada was interviewed by trained lay interviewers using the Diagnostic Interview Schedule (DIS) (73% completion rate). An average of 2.8 years later, a systematic random sample of 1964 subjects was reinterviewed (an 86% completion rate) using the DIS and a health care utilization questionnaire. After adjusting for age and sex, the reinterview sample was representative of those with and without a diagnosis at the first interview. Results: Of the 1964 subjects, 570 (31%) met criteria for a DIS/DSM-III diagnosis in the year preceding the interview (one-year prevalence rate). These diagnoses included generalized anxiety disorder (GAD) and posttraumatic stress disorder (PTSD). For those with a diagnosis, sex, age, marital status, education, employment, and income were examined as determinants of help-seeking. Only sex (female) and age (under 45) were significant predictors. Comorbidity was highly significant: the help-seeking rate for those with one diagnosis was 20.3%; for those with more than one diagnosis, the rate was 42.8% (OR = 2.94, χ2 = 31.4, df = 1, P < 0.001). Just over 28% of those with a diagnosis saw any health care professional, and 7.7% of those without a diagnosis sought help for a mental or emotional problem. A specific diagnosis made a difference: 46.7% of those with a major depressive episode sought help, but only 16.0% of those with alcohol abuse or dependence sought care. Conclusion: Major determinants of help-seeking are sex (female), age (under 45), severity of the illness, and comorbidity. A surprisingly high proportion of those with a disorder (72%) do not seek help, and over one-third of those seeking help do not have a current DIS/DSM-III disorder.