During early childhood, harsh and emotionally negative parent-child exchanges are expected to increase children's risk for developing later conduct problems. The present study examined longitudinal associations between the quality of parenting responses and children's distress reactivity during children's second year of life. Forty-seven mother-child dyads completed observational assessments of children's distress reactivity and mothers' harsh and supportive parenting when children were 12 and 24 months of age. Results indicated that mothers' contingent harsh parenting responses to children's non-compliance when children were 12 months of age predicted increases in children's observed distress from 12 to 24 months, but children's level of distress at 12 months did not predict change in harsh parenting responses over the same time period. In contrast, supportive parenting contingent responses did not predict declines in children's distress reactivity, although children's distress reactivity predicted declines in mothers' supportive parenting responses from 12 to 24 months. Results are discussed in terms of the implications of the quality of parent-child interactions as a point of entry onto developmental pathways of risk.