This study was designed to investigate whether or not degree of child maltreatment is related in some meaningful way to the interactional characteristics of the mother/infant dyad and to the infant's developmental status. A group of 53 mother/infant dyads was divided into five diagnostic groups: nonaccidental trauma combined with failure-to-thrive, nonaccidental trauma combined with iron-deficiency anemia, nonaccidental trauma only, neglect only, and normal controls. During a feeding session, qualitative differences were found in the relational characteristics of dyads in which multiple forms of child maltreatment existed. Developmental examinations revealed that infants subjected to severe abuse and neglect were significantly retarded in their mental and motor development, as compared to the remaining index and control groups. The results were interpreted to suggest that relational disturbances are at the core of the problem of infant maltreatment and that on the basis of interactional symptomatology, two broadly different clinical conditions may be identified. (Author/MP)