This study examined parent ratings of problems and competencies in a population of infants-toddlers (N=60) from 12 to 35-months who had a variety of developmental delays as a consequence of either Down's Syndrome or a premature birth using the Infant-Toddler Social and Emotional Assessment (ITSEA; Briggs-Gowan, 1996). The study investigated whether; (1) developmentally delayed infants (premature and Down's Syndrome) have more behaviour problems and are less competent socially and emotionally than normally developing infants; and (2) infants born prematurely and infants with Down's syndrome display mixed patterns of problematic behaviour that are significantly different from each other. Patterns of strengths and weaknesses in social­ emotional development were used to compare the profiles associated with infants born prematurely or with Down's Syndrome with normal developing infants. Findings revealed that infants with developmental delay demonstrated a developmental trajectory of problems and competencies that varied from normally developing infants. However, premature infants were found to display significantly more developmental lags from normally developing infants, particularly in the skills of the competence scale. The results are discussed in terms of the hypotheses and the need for a comprehensive early intervention programme for infants with developmental delay who present with social­ emotional problems. Information resulted in increased insight into the later risks to these infants' social-emotional development through the understanding of the problems they experience and a step toward improving the dearth of studies in the area of social­ emotional development.