BACKGROUND: Suicide is the third-leading cause of death among Illinois residents aged 15 to 24 years. The Illinois Violent Death Reporting System (IVDRS) was developed to help prevent these deaths by providing timely, complete data. Understanding the circumstances surrounding suicide for those aged 15 to 24 years who are not receiving mental health treatment can help others: (1) recognize signs of potential crisis and (2) connect them to mental health treatment. METHODS: The IVDRS data were collected from five Illinois counties-Cook, DuPage, Kane, McHenry, and Peoria-from 2005 to 2010. All cases with the manner suicide, aged 15 to 24 years, were extracted for analysis. Data were described using frequencies and percentages, and statistical differences between groups were determined using chi analysis. RESULTS: There were a total of 386 suicides in those aged 15 to 24 years in IVDRS from 2005 to 2010. Most 15- to 19-year-olds (67%) and 20- to 24-year-olds (78%) were not receiving mental health treatment at the time of death. Among those not receiving mental health treatment, 22% and 13% of those aged 15 to 19 and 20 to 24 years, respectively, had disclosed their intent to commit suicide to another. One third were identified as being depressed or in a depressed mood (not necessarily a clinical diagnosis) in both age groups. One quarter in both age groups experienced a crisis (current, acute precipitating, or forthcoming event) within 2 weeks of their suicides. CONCLUSIONS: The majority of adolescents and young adults were not in mental health treatment at the time death. Among those not in mental health treatment at the time of death, the 15- to 19-year-olds were more likely to share their suicidal intentions than the 20- to 24-year-olds. LEVEL OF EVIDENCE: Epidemiological study, level IV.