The Youth Risk Behavior Survey (YRBS) is an epidemiologic surveillance system that was established by the U.S. Centers for Disease Control and Prevention (CDC) to help monitor the prevalence of behaviors that not only influence youth health, but also put youth at risk for the most significant health and social problems that can occur during adolescence and adulthood. To monitor priority health-risk behaviors in each of these six categories and obesity and asthma among youth and young adults, CDC developed the YRBS. The YRBS has been conducted biennially since 1991 in Montana. The purpose of the YRBS is to assist educators and health professionals in determining the prevalence of the aforementioned health-risk behaviors among youth. This report describes the results of the survey and the methods used to conduct the survey. The results will be used to focus the continuing development of statewide comprehensive health education and to reduce those health behaviors that place Montana youth at risk. Survey results are presented in the following parts: (1) Introduction; (2) Survey Methods; (3) Frequency Distributions; (4) Graphs; (5) 10-Year Trend Analysis; and (6) 2017 Comparative Data Results (Montana High School YRBS and Subgroups). [Additional funding for YRBS was provided by the Montana Board of Crime Control, Montana Department of Public Health and Human Services, Billings Area Indian Health Service, and Montana Department of Transportation.]