Background Previous research has documented that exposure to parental separation/divorce during childhood can be associated with long‐term consequences into adulthood. This study sought to extend this literature by examining associations between childhood exposure to parental separation/divorce and later parenting behavior as an adult in a New Zealand birth cohort. Methods Data were drawn from the Christchurch Health and Development Study (CHDS), a longitudinal study of a birth cohort of 1,265 children born in 1977 in Christchurch, New Zealand. Information about exposure to parental separation and divorce was gathered annually from birth to 15 years. At the 30‐year follow‐up, all cohort members who had become parents (biological or nonbiological) were assessed on several parenting dimensions (sensitivity, warmth, overreactivity, inconsistency, quality of child management, and physical punishment). Results The analyses showed that exposure to more frequent parental separation in childhood and adolescence was associated with lower levels of parental sensitivity and warmth, greater overreactivity, and an increased use of physical punishment as a parent, after controlling for a wide range of family socioeconomic and psychosocial factors, and individual child characteristics. Conclusions The findings suggest that as exposure to parental separation increases, so does the likelihood of experiencing multiple developmental challenges in childhood and adolescence. As an adult, these life‐course experiences can have small but significant associations with the quality of parenting behavior.