The breast self-examination (BSE) practices of 1,453 Hispanic women in Phoenix, Arizona and San Diego, California were the focus of this study. Variables proposed as factors that influence the frequency and proficiency of BSE were demographic variables, particularly language and level of acculturation, having been taught BSE by a health professional, and experience with the disease. Results indicate that even though the majority of the women at both the Phoenix (78.1%) and San Diego (83.7%) sites had been taught BSE by a professional and most women in Phoenix (62.5%) and San Diego (63.4%) reported performing BSE within the past month, only 0.7% of the women at both sites were found to be proficient in the technique of BSE. Further, results indicate that language and acculturation were correlated with whether or not a woman performed BSE. These findings suggest that BSE education classes must provide information and techniques that promote proficiency in BSE, and must be designed to meet the unique needs of Hispanic women, particularly those of low acculturation levels.