The effects of ethnicily and socioeconomic status on the use of screening mammograms were assessed for a probability sample of Chamorro, Filipino, White, and other Asian and Pacific island women residing on Guam. Using logistic regression analysis, we found that socioeconomic status significantly influenced the use of screening mammograms among Chamorro and Filipino women while strong ethnic effects remained for other Asian and Pacific island women. Age had a significant influence of the use of screening mammograms. Marital status and having a young child in the home were not significant predickx variables.