This is a five-year prospective randomized trial comparing two intervention conditions designed to facilitate substance abuse treatment entry and enhance retention in order to reduce the behaviors associated with HIV and HCV risk among injection drug users (IDUs) and to improve client overall functioning. The overall goal of this project is to compare strengths-based case-management (CM) to an enhanced version of CM that uses case managers to facilitate a therapeutic alliance (CM/FTA) among out-of-treatment IDUs in Denver.