Abstract Background: Paternal perinatal mental health influences subsequent child development, yet is under-investigated. This study aims to examine the impact of different timings of paternal perinatal anxiety (prenatal-only, postnatal-only, and both pre-and postnatally) on children’s subsequent emotional and behavioral difficulties. Method: We used data from the Avon Longitudinal Study of Parents and Children and tested the prospective associations between anxiety in fathers and adverse mental health outcomes in children at 3 years, 6 months and 7 years, 7 months. Results: Children whose fathers were anxious in the perinatal period were at higher risk of subsequent adverse outcomes, compared to children whose fathers were not anxious perinatally. At 3 years, 6 months, the highest risk group was the one with fathers anxious prenatally-only; compared to children with non-anxious fathers, children in the prenatal-only group were significantly more likely to present mental health difficulties, measured by total problems (unadjOR = 1.82, 95%CI [1.28, 2.53]). At 7 years, 7 months, children exposed to paternal anxiety both pre- and postnatally were at higher risk of any psychiatric disorder (unadjOR = 2.35, 95%CI [1.60, 3.37]) compared to the non-anxious group. Conclusions: Paternal perinatal anxiety is a risk factor for child adverse outcomes, even after accounting for maternal mental health, child temperament, and sociodemographic factors, and should not be overlooked in research and clinical practice.