Background: A father who does not know how to assist the mother in relieving labor pains may experience a sense of powerlessness and anxiety. The objective of this study was to evaluate how an education program for expectant fathers who attended their partners' labor and birth affected their anxiety.Methods: In a randomized controlled trial, 87 expectant fathers who attended their pregnant partners through labor and birth at a hospital in central Taiwan were allocated by block randomization to an experimental (n = 45) and a control (n = 42) group. The men completed their basic personal information, a childbirth expectations questionnaire, and a Trait Anxiety Inventory when they were recruited. Two hours after birth of their child, all the expectant fathers completed a State of Anxiety Inventory.Results: Our results showed no statistically significant differences between the experimental and control groups of fathers in trait anxiety and their prenatal childbirth expectations. After analysis of covariance (ANCOVA) was applied to correct for education level, sources of childbirth information, attendance at Lamaze childbirth classes, and childbirth expectations at baseline, the effect of the childbirth program was significant for the postnatal level of anxiety (F = 3.38, p = 0.001).Conclusions: The study findings justify the clinical implementation of a birth education program based on the self-efficacy theory as an effective means of reducing anxiety among expectant fathers.