A smoking cessation and relapse prevention intervention was tested in an urban, prenatal clinic serving predominantly low-income, African-American women. At their first prenatal visit, 391 smokers were randomly assigned to an experimental (E) group to receive usual clinic information plus a prenatal and postpartum intervention or to a control (C) group to receive only usual clinic information. The intervention consisted of individual skills instruction and counseling by a peer health counselor on the use of a self-help cessation guide and routine clinic reinforcement. Among the E group (n = 193), 6.2% were cotinine-confirmed quitters at third trimester and among the C group (n = 198) the quit rate was 5.6%. Quitters were light smokers at entry into prenatal care. Many had tried to quit smoking at least once prior to pregnancy.