Objectives Despite the benefits of breastfeeding, less than a fifth of American mothers breastfeed for the recommended duration. Paternal support plays a major role in maternal and child health outcomes; however, the influence of paternal pregnancy intention on breastfeeding duration is under investigated. This study examines the relationship between fathers' pregnancy intention and breastfeeding duration. Methods Data from the 2011-2013 National Survey of Family Growth were analyzed using cross-sectional methodology. Women who were pregnant, never received medical help to become pregnant, whose partner was aged 18-49 years, and who responded to questions related to paternal pregnancy intention and breastfeeding were included in the analysis (N = 2089). Multinomial logistic regression, odds ratios and 95 % confidence intervals were calculated. There was a statistically significant interaction between father's age and father's pregnancy intention (P = 0.0385) and all models were stratified by paternal age. Results Fathers aged 18-24 years with a mistimed pregnancy were 2.3 times more likely to have a child who was never breastfed, (AOR 2.27, 95 % CI 1.39-3.70) and 1.7 times more likely to have a child who was breastfed 6 months or less (AOR 1.69, 95 % CI 1.28-2.23) compared to fathers with an intended pregnancy. No statistically significant association was observed among fathers aged 25-49 years. Conclusion Findings from this study show a relationship between mistimed pregnancies and breastfeeding duration among younger fathers. Healthcare professionals should develop breastfeeding interventions targeting fathers and young families.