Introduction: The aim of the present study was to investigate the association between exposure to fathers' alcohol consumption and offspring's own risk of alcohol-related hospitalization. Methods: Data on circumstances in childhood and adolescence, e.g. fathers' alcohol consumption at different levels (never, rarely, occasionally, often), parental divorce, as well as offspring's own risky use of alcohol, smoking and mental health were collected among 49,321 men (sons), born in 1949-51, during conscription for compulsory military training in 1969/70, i.e. at ages 18-20. Data on alcohol-related diagnoses were collected from the Swedish In-patient Care register 1973-2009. Results: The relative risk of alcohol-related diagnoses among sons after the age of 20 increased with increasing level of alcohol consumption in the fathers. Compared with sons whose fathers never drank alcohol, those with fathers who drank alcohol occasionally or often had an increased hazard ratio (HR) of later hospitalization with alcohol-related diagnoses of 1.77 (95% confidence interval (CI)=1.57-1.99) and 3.69 (CI 95% = 3.16-4.32), respectively. The associations were markedly stronger when the men were followed from age 40 and onwards compared with follow-up between 20 and 40 years of age. Conclusion: Father's alcohol consumption was associated with an increased relative risk of alcohol-related hospitalization in offspring in adulthood.