There is limited evidence to inform effective screening practices for identifying fetal alcohol spectrum disorder (FASD) in forensic mental health settings. This study sought to explore the potential use of four FASD screening tools in a Canadian forensic mental health program. In total, 151 patient charts were screened using the FASD Screening and Referral Tool for Youth Probation Officers and the FASD Risk Assessment Questions A subset of current patients (n = 41) also completed screening interviews using the FASD Brief Screen Checklist and Life History Screen. Based on passive ascertainment via chart review, we found six cases of confirmed/suspected FASD (4%), evidence of PAE in 7% of the sample, and signs of maternal alcohol use during childhood in 17% of cases. Across the entire sample and four screening tools, the proportion of potentially ‘positive’ FASD screens based on exploratory evaluation ranged from 10% to 33%. Exploratory screening outcomes varied considerably between tools. Findings highlight the need for additional research to identify rates of FASD in forensic mental health settings, and to develop evidence-based screening and assessment approaches, and practice guidelines, for this setting.