Although prevention of mother-to-child HIV transmission (PMTCT) programs are predicated on maternal behavior change, little is known about sociocultural factors affecting maternal-child care practices in this arena. The authors used narrative methods (key informant workshops, questionnaires, focus groups, and case study analysis) to explore how sociocultural context shapes adolescent mothers' ability to adhere to programmatic recommendations in rural and urban South Africa. The study aims were to understand the extent to which mothers' decisions are borne out in PMTCT-related practices and to identify contextual elements that affect the link between individual resolutions and action. The results revealed rural adolescents as less likely than urbanites to successfully implement most PMTCT-related practices. HIV stigma, family decision making, and cultural norms surrounding infant feeding hampered mothers' efforts to implement practices that would decrease the risk for infant infection. Barriers to behavior change were analyzed along four domains: history, culture, gender, and power. Methodological aspects and programmatic implications are discussed. (Contains 1 figure and 1 table.)