Individuals with substance abuse and mental health problems are common in prisons and jails, but relatively little is known about the health or health services utilization of inmates with these types of problems. This study, therefore, focuses on prisoners who self-reported receiving a prior diagnosis from a physician or a psychologist who indicated they had 1) substance abuse problems only, 2) mental health problems only, and 3) substance abuse and mental health problems. A fourth group of prisoners who reported no diagnoses were included as the "no problems" group. Comparisons were made on reports of lifetime health problems, use of preventive health services, and use of medical services. Findings showed the substance abuse and mental health problems group had the most serious health problems profiles. Use of preventive health services was similar across all four groups, but the substance abuse and mental health problems group reported significantly greater use of the emergency room and more hospital stays both for their lifetime and in the year prior to their current incarceration. The policy and practical relevance of the findings are discussed.