AimsHomeless mothers with young children in their care contend with high rates of substance use and low self-efficacy. However, a limited number of studies have examined these outcomes associated with housing and supportive services. DesignParticipants were randomly assigned to: (1) housing + support services (n = 80), (2) housing-only (n = 80), or (3) services as usual (SAU) (n = 80) and were re-assessed at 3-, 6-, 9- and 12-months postbaseline. SettingsThe study recruited a community-based sample from homeless service agencies and advertisements in a large Midwestern city. ParticipantsThe study recruited two hundred forty (N = 240) women between the ages of 18 to 24 years, experiencing homelessness and with a substance use disorder (SUD) who also had a biological child under the age of 6 years in their care. MeasurementsWe measured frequency of alcohol and drug use using the Form 90 semi-structured interview, and self-efficacy using Pearlin and Schooler's (1978) 7-item Mastery Scale. FindingsOverall, mothers showed significant improvement in substance use and self-efficacy over time in each condition. However, as expected, patterns of change differentiated intervention groups with more mothers showing better substance use and self-efficacy outcomes in housing + supportive services than in SAU. Unexpectedly, more mothers in SAU showed better outcomes than those in housing-only. ConclusionsSubstance use decreased and self-efficacy increased over time, but patterns of change characterized the intervention groups. In particular, findings suggest that when providing housing to this population, supportive services should also be offered.