This article presents results of the first randomized experimental evaluation of a legal assistance program for low-income tenants in New York City's Housing Court. The results demonstrate that the provision of legal counsel produces large differences in outcomes for low-income tenants in housing court, independent of the merits of the case. For example, only 22% of represented tenants had final judgments against them, compared with 51% of tenants without legal representation. Similarly large advantages for tenants with an attorney also were found in eviction orders and stipulations requiring the landlord to provide rent abatements or repairs. In addition, the results suggest that a program of legal assistance for low-income tenants would not increase significantly the number of appearances in court, although it would increase the number of days to final judgment. The program may enhance the efficiency of adjudication by reducing the number of motions filed, particularly post-judgment motions. Limitations and policy implications of the study are discussed.