Objective. We examined breast cancer treatment experiences of and outcomes for Latinas in Los Angeles County. Methods. We conducted a population-based survey of women who were diagnosed with breast cancer between December 2001 and November 2002 (n = 910) to evaluate the types of treatments received, communication with clinicians, and satisfaction. Results. About two thirds were non-Latina White, 18.8% were African American, and 18.9% were Latina (with 11.0% preferring English and 7.9% preferring Spanish). The rest indicated other ethnic groups. Latinas who preferred Spanish were more likely to experience a delay of 3 months or more from diagnosis to surgical treatment (36.4% vs 9.1% for non-Latina Whites, 18.6% for African Americans, and 12.7%, for other Latinas, P<.001). African Americans and Latinas who preferred Spanish had very low rates of reconstruction (13.8% and 9.2%, respectively, compared with 42.1% for Whites and 34.5% for Latinas who preferred English, P = .009). Latinas who preferred Spanish had the highest odds ratio for low satisfaction. Conclusion. Latinas who preferred Spanish received different treatments and perceived a different treatment experience than did other cultural groups. doi: 10.2105/AJPH.2004.057950)