This study tested whether maternal sensitivity and child security are related during early childhood and whether such an association is found in different cultural and social contexts. Mother-child dyads (N = 237) from four different countries (Colombia, Mexico, Peru, and the United States) were observed in naturalistic settings when children were between 36 and 72 months of age. Maternal and child behavior during interactions at home and in the playground were described using Q methodology. Findings reveal that across cultures, concurrent maternal sensitivity and more specific behavioral domains of maternal care (e.g., contributions to harmonious interactions and secure base support) are important for children's attachment security during early childhood. Implications for the study of attachment relationships beyond infancy and in diverse contexts are highlighted.