The present study examined bidirectional effects between maternal and paternal parenting styles (authoritative, authoritarian, permissive) and infant temperament (negative affect, orienting/regulatory capacity, surgency) in a diverse sample of 201 mothers and 151 fathers. Using 3 waves of longitudinal data (prenatal, 6 months, and 18 months), this study examined (a) whether maternal and paternal parenting styles prospectively predicted infant temperament; (b) whether mother- and father-reported infant temperament domains predicted parenting styles at 18 months; and (c) whether infant temperament and parenting styles at 6 months predicted parent-reported externalizing and internalizing problem behaviors at 18 months. Mothers and fathers reported on their expected parenting styles at all three waves, infant temperament at 6 months, and their toddler's emerging internalizing and externalizing problems at 18 months. Prospective parenting style effects revealed that maternal authoritative and permissive parenting style predicted infant orienting/regulatory capacity. Child evocative effects indicated infant orienting/regulatory capacity and negative affect predicted greater maternal permissive parenting style. Significant prospective parenting style effects on infant temperament and child evocative effects on paternal parenting style were largely not observed. Several parenting styles and infant temperament domains at 6 months predicted toddlers' externalizing and internalizing problem behaviors but results differed by parent. Findings suggest maternal prenatal perceptions of parenting style predict infant temperament, but temperament can also affect subsequent parenting. More research is needed to identify fathers' bidirectional effects including how fathering is affected by their children's characteristics. (PsycINFO Database Record (c) 2019 APA, all rights reserved).