Research relevant to planning and practice in the area of infant mental health is discussed in this paper. First, three examples of research approaches that reflect current attitudes are given. The first example represents those studies in which there is an effort to closely coordinate physiological and behavioral studies. The second example represents studies focusing on the infant and the caretaking environment as a living, biological system. The third example represents interest in the systematic study of affect development, some of it with the goal of theory building. It is pointed out that these three large and overlapping areas of currently intense inquiry are applicable to clinical practice in the early years and each depends partly on the study of deviations in development and in the parent-child relationship. In subsequent material, several other categories of studies relevant for the field of infant mental health are cited in condensed form. These include studies of (1) congenital characteristics and individual tendencies, (2) vulnerability and resilience, (3) competence and effectance motivation, (4) separation-individuation, (5) deprivation, separation and loss, (6) parent-infant interaction, (7) speech development, (8) parent-child attachment behavior and disorders of attachment, and (9) early intervention. (Author/RH)