Purpose: Umbilical and epigastric hernia repair are common surgical procedures; however, the nationwide gender and age-specific prevalence of these repairs is unknown, and this knowledge could form the basis for new studies. Methods: A nationwide register-based study covering all people living in Denmark on December 31st, 2010 was performed. Within this population all umbilical and epigastric hernia repairs from January 1st, 2006 to December 31st, 2010 were identified using data from the Danish National Hospital Register, and 5-year prevalence estimates were calculated. Results: The study population covered 5,639,885 persons (49 % males). A total of 10,107 patients (68 % males) were operated for an umbilical hernia and 2412 patients (55 % males) were operated for an epigastric hernia. The age-specific 5-year prevalence differed for both hernia types. The highest 5-year prevalence of umbilical hernia repairs was seen in males aged 60–70 years with a 5-year prevalence of 0.53 % (95 % CI 0.51–0.56 %) and the highest age-specific 5-year prevalence of epigastric hernia repair was seen in 40–50 year females with a 5-year prevalence of 0.086 % (95 % CI 0.077–0.095 %). Conclusion: The gender and age-specific 5-year prevalence of umbilical and epigastric hernia repair differed in a nationwide population.