Background: Despite the evidence that fatherhood has a long-term positive and protective effect on men's health, there is also evidence that fatherhood in the perinatal period can be complex and demanding. Due to the potential increase in stressors in the perinatal period, there is reason to hypothesise that it is a time of increased stress for fathers. However, it is not clear how significant a problem stress is for fathers during this stage of life. This is in part, due to the fact that the available research has not been systematically reviewed. Purpose: The purpose of this systematic review was to critically appraise the empirical evidence that examined stress in fathers in the perinatal period. Design: systematic review. Methods : A systematic review protocol was developed and registered with PROSPERO (Reference number: CRD42016035821). The review was guided by the PRISMA reporting process. Electronic databases Medline, CINAHL, the Cochrane Library, PsycARTICLES, PsycINFO, Psychology and Behavioural Sciences Collections were searched to identify studies that met the inclusion criteria. Studies that researched fathers in the perinatal period were included if stress was the principal focus of the research, if stress was in the title and/or aim of the study or if stress was an outcome or dependent variable. Data were extracted and presented in narrative form including tables and figures. Findings :Eighteen studies met the inclusion criteria. The findings indicate that fathers experience stress in the perinatal period, particularly at the time of birth. Stress levels were found to increase from the antenatal period to the time of birth, with a decrease in stress levels from the time of birth to the later postnatal period. There are a number of factors that contribute to stress in fathers in the perinatal period and these included negative feelings about the pregnancy, role restrictions related to becoming a father, fear of childbirth and feelings of incompetence related to infant care. The review found that stress has a negative impact on fathers, with higher stress levels contributing to mental health issues such as anxiety, depression, psychological distress and fatigue. Key conclusion: During the perinatal period fathers experience stress and face unique stressors that can impact negatively on their health and social relationships.