Toddlers and children, aged 6 to 38 months, with their mothers, were observed in free-play that included a hand and standing mirror. The mother-toddler interaction was assessed according to a proposed profile that described 34 categories of maternal behaviors, such as empathy, attunement, acceptance of the child as a separate individual, and capacity to provide a referencing framework. Fourteen maternal modes or styles, such as consistency, genuineness, intrusiveness, and pleasure in maternal role, also were coded. The global ratings of maternal behaviors were related to the behaviors in front of the mirrors as outlined by Amsterdam (1972). Initial observations suggest that deviant mirror behaviors parallel deficits in the mother-toddler interaction. In contrast, mirror behavior is appropriate or beyond the chronological age if the mother-toddler interaction is satisfactory. Because mirror behavior reflects a sense of self and covaries with the quality of the mother-toddler interaction, the behavior in front of the mirror may be used as a clinical diagnostic tool.