We present a cost-utility analysis based on data from the Housing and Health (H&H) Study of rental assistance for homeless and unstably housed persons living with HIV in Baltimore, Chicago and Los Angeles. As-treated analyses found favorable associations of housing with HIV viral load, emergency room use, and perceived stress (an outcome that can be quantitatively linked to quality of life). We combined these outcome data with information on intervention costs to estimate the cost-per-quality-adjusted-life-year (QALY) saved. We estimate that the cost-per-QALY-saved by the HIV-related housing services is $62,493. These services compare favorably (in terms of cost-effectiveness) to other well-accepted medical and public health services.