Stability and change in parental extraversion and neuroticism were studied in transaction with their views of their child's temperament from the age of six months to the age of five-and-a-half years in 109 mother–father–child triads (parent–daughter: n = 61, parent–son: n = 48). While parental traits showed high stability, infants' higher positive affectivity predicted an increase in parental extraversion over 5 years, and infant's higher activity predicted a decrease in parental neuroticism. Parent-rated temperament showed expected heterotypic continuity. Initially higher parental extraversion predicted an increase in the child's effortful control, and higher parental neuroticism predicted an increase in the child's negative affectivity. The results indicate that parental personality and child temperament develop in transaction promoting change in each other. Copyright © 2008 John Wiley & Sons, Ltd.