AbstractOver the past three decades, harm reduction has gradually become more prevalent among social workers and is now viewed as an instrumental approach in treating people with drug and alcohol problems. Although there have been several studies that described how harm reduction approaches were applied in Housing First (HF) settings, there are few studies that have described social workers’ perspectives of their philosophical attitudes regarding harm reduction in HF settings. The purpose of this study was to understand social workers’ perspectives of their philosophical attitudes toward harm reduction services and how those attitudes were apparent in their interactions with substance-using HF clients. A generic qualitative research design was employed with a purposive sample of six social workers with work experience in HF settings. Data were collected through individual, semistructured interviews comprised of 10 interview questions. Thematic analysis revealed three emergent themes in the data set: support of HF and a positive philosophical attitude about harm reduction in HF settings, programmatic challenges exist in HF settings, and HF programs align with the concept of social justice. The findings from this study support positive social change by identifying micro, mezzo, and macro implications that could be used to support the provision of harm reduction services to clients living in HF programs