A single-blind, randomized, placebo-controlled study was performed to evaluate auricular acupuncture (AAc) in the treatment of cocaine addiction. Two linked but concurrent studies were done. In Study 1, residential clients (N = 236) were randomized to true acupuncture (Ac), sham Ac, and conventional treatment without Ac. Treatment group subjects received Ac at three ear points considered to be specific for the treatment of substance abuse (SA). Control subjects received three nonspecific (sham) points. In Study 2, day treatment clients (N = 202) were randomized to one of three dose levels of true Ac (28, 16, or 8 treatments). Subjects received Ac at five, rather than three, specific ear points. Nonspecific (sham) points were not used in Study 2. With rare exception, the data failed to identify significant treatment differences among the true and sham Ac, and psychosocial groups. Furthermore, no differences were observed among the three dose levels of true Ac.