This longitudinal study examined posttraumatic stress disorder (PTSD) and anxiety symptoms among men attending the birth of their first offspring. Furthermore, we examined the moderating role of anxiety sensitivity (AS) and intolerance of uncertainty in the association between exposure to stress during birth and PTSD and anxiety symptoms. Participants were Israeli men (n = 171) who were assessed with self-report questionnaires during the third trimester of pregnancy (T1) and approximately a month following birth (T2). Results show that the rates of postnatal PTSD and anxiety symptoms were relatively low. Subjective exposure to stress during birth and AS predicted PTSD in T2, above and beyond other negative life events and PTSD in T1. In addition, AS moderated the relations between subjective exposure to stress during birth and PTSD symptoms. Pregnancy and childbirth professionals may benefit from the insight that men with high levels of AS might experience childbirth as a highly stressful situation with possible posttraumatic stress symptoms.