“Motherhood penalty” and “fatherhood premium” refer to gender-specific hypotheses about the effects of fertility on parents’ labor force outcomes. While past research using observational data has found evidence consistent with the motherhood penalty and fatherhood premium hypotheses, these empirical findings remain inconclusive due to the potential threat of selection biases. China’s one-child policy and its regional variation in exemptions to the policy when a first child is a girl enables us to use the gender of the first child as a powerful instrumental variable (IV) in identifying the gendered fertility effects. Based on the IV approach, this paper examines the gender-specific fertility effects on parents’ time use, income, and subjective well-being, using data from the nationally-representative 2010 China Family Panel Studies. Results show that having more children makes fathers spend significantly more time at work and less time taking care of other family members. Mothers, on the other hand, report better subjective well-being with more children. Regarding specific subjective outcomes, fathers gain self-confidence in both career and the future, and mothers are happier, more satisfied with life and report higher social relationship quality. In sum, we find premiums for both fathers and mothers and penalty for neither. We interpret the positive effects of parenthood within the context of China’s highly restrictive one-child family planning policy. However, the gendered distribution of the fertility effects reveals within-household gender-role specialization.