To assess the efficacy of Korean Immigrants and Mammography-Culture-Specific Health Intervention (KIM-CHI), an educational program for Korean American (KA) couples designed to improve mammography uptake among KA women.A two-group cluster randomized, longitudinal, controlled design.50 KA religious organizations in the Chicago area.428 married KA women 40 years of age or older who had not had a mammogram in the past year. The women and their husbands were recruited from 50 KA religious organizations.Couples were randomly assigned to intervention or attention control groups. Those in the KIM-CHI program (n = 211 couples) were compared to an attention control group (n = 217 couples) at baseline, as well as at 6 and 15 months postintervention on mammogram uptake.Sociodemographic variables and mammography uptake were measured. Level of acculturation was measured using the Suinn-Lew Asian Self-Identity Acculturation Scale. Researchers asked questions about healthcare resources and use, health insurance status, usual source of care, physical examinations in the past two years, family history of breast cancer, and history of mammography.The KIM-CHI group showed statistically significant increases in mammography uptake compared to the attention control group at 6 months and 15 months postintervention.The culturally targeted KIM-CHI program was effective in increasing mammogram uptake among nonadherent KA women.Nurses and healthcare providers should consider specific health beliefs as well as inclusion of husbands or significant others. They also should target education to be culturally relevant for KA women to effectively improve frequency of breast cancer screening.