Objectives The goals of this study were to assess: (a) the involvement of fathers and mothers in overall and nighttime infant caregiving; (b) the links between paternal involvement in infant care and infant sleep patterns during the first 6 months. Methods Fifty-six couples recruited during their first pregnancy, participated in the study. After delivery (1 and 6 months), both parents completed a questionnaire assessing the involvement of fathers relative to mothers in infant caregiving. Infant sleep was assessed using actigraphy and sleep diaries. Results Mothers were significantly more involved than fathers in daytime and nighttime caregiving. A higher involvement of fathers in overall infant care predicted and was associated with fewer infant night-wakings and with shorter total sleep time after controlling for breastfeeding. Conclusions The findings highlight the importance of including fathers in developmental sleep research. Future studies should explore mechanisms underlying the relations between paternal involvement and infant sleep.