This article examines the quality of maternal mind-mindedness among adult and adolescent mothers, using an assessment of the appropriateness and emotional valence of maternal mind-related comments while interacting with their infants. Twenty-nine adult mothers and 69 adolescent mothers participated in two assessments with their 18-month-old infants. Results showed that adult mothers used more mind-related comments when interacting with their child, especially comments referring to infant mental states. Adult mothers also used more appropriate and positive mind-related comments. Home observations and strange situation assessments revealed that two dimensions of mind-mindedness were associated with maternal sensitivity and three with infant attachment in adult mothers, whereas only one dimension was associated with maternal sensitivity in adolescent mothers.