Harm reduction approaches to recovery from alcohol or other drug (AOD) use underpin housing-led homeless services, particularly Housing First (HF). HF programmes aim to promote recovery by reducing harmful consequences of use rather than requiring abstinence. As part of a larger questionnaire-based study with homeless services users in eight European countries, we analysed data collected from adults engaged with either HF programs or traditional services (TS) on measures of problem-related alcohol, illicit drug use and service utilization for AOD use (n = 565). Although rates of alcohol and illicit drug use were similar, participants in TS reported higher quantities of alcohol use, more binge drinking, injury-related alcohol and illicit drug use, more polysubstance use, and more problematic illicit drug use. Participants in TS also reported higher rates of emergency room and inpatient/residential services for AOD use, while rates of community-based services for AOD use were similar. Results are discussed in relation to previous findings regarding the rates of AOD and service use among homeless services users in HF and TS, the importance of harm-reduction strategies, and suggestions for policy and practice in homeless services for adults with alcohol- and drug-related support needs.