The malleability of fertility-related attitudes and behavior was studied by analyzing data collected from cross-sectional groups of Filipino migrants who had lived in the United States for varying lengths of time, in conjunction with data from a comparison group of Caucasians from the Filipinos’ neighborhoods. With increasing number of years lived in the United States, Filipino migrants’ fertility-related knowledge, attitudes, and desires became increasingly similar to those of the Caucasian group, but their contraceptive behavior did not. While approximately equal numbers of Filipinos and Caucasians were contracepting, Filipino couples regardless of duration of stay in the United States were using less effective methods with less regularity. Despite these contraceptive behavior patterns, Filipino migrants perceived that they would have 0.32 fewer children in the United States than they would have had had they remained in the Philippines. By far the most predominant reason given by Filipino respondents for changing fertility patterns in the United States was the difficulty of obtaining child care in the new environment.