According to attachment theory, the quality of care plays a key role in the organization of infants' secure base behavior across contexts and cultures. Yet information about attachment relationships in a variety of cultures is scarce, and questions remain as to whether Ainsworth's conceptualization of early care quality (sensitivity; M. D. S. Ainsworth, M. C. Blehar, E. Waters, & S. Wall, 1978) is appropriate for characterizing caregiving behavior in different groups and whether culturally specific descriptions of early care are related to conventional measures of maternal sensitivity and to infants' security. In this naturalistic study of mother-infant interactions in Colombia, scores on different domains of maternal care were obtained through ethnographic methodology, and conventional Q-sort scores for maternal and infant behavior were obtained. Findings are discussed in terms of the cross-cultural generality of the sensitivity construct and the sensitivity-security link and of the relevance of naturalistic open-ended studies in different contexts.