Reciprocal associations between the Big Five personality traits and parenting stress--including both parents' feelings of their distress and perception of their incompetence as parents--were studied with 248 participants (49% of which were males). Longitudinal data, collected at ages 33/36, 42 and 50 years, were used. Cross-lagged path analysis revealed that in case of both mothers and fathers, neuroticism at age 33 predicted high parenting stress, and extraversion at age 33 predicted low parenting stress at age 42. Also, parenting stress at age 36 predicted high neuroticism and low extraversion at age 42. From age 42 to 50, only high parenting stress contributed to low neuroticism. Thus, more significant cross-lagged associations of neuroticism and extraversion with parenting stress were detected in early middle age, i.e., from age 33/36 to 42, as compared to later midlife, i.e., from 42 to 50 years of age. The reciprocal associations between parenting stress and neuroticism and extraversion were similar for both mothers and fathers. High conscientiousness at age 42, however, predicted low parenting stress at age 50 only in fathers.