Objective: Although parental alcohol use disorder (AUD) increases risk for alcohol problems in offspring, no studies have evaluated the odds of AUD in offspring based on the number of biological parents with AUD (0, 1, or 2) in a population-based national sample. The purpose of this study was to investigate the relationship between the number of AUD parents and prevalence of AUD in offspring. Method: This study utilized data from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions, which assessed AUD using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV Version (main outcome variable). We analyzed the sample (n = 40,374) to investigate the effect of the number of AUD parents on lifetime AUD in offspring. In a subgroup analysis, gender differences were examined. Results: 22% of adults in the United States had at least 1 biological parent with AUD. Compared with offspring of non-AUD parents, offspring of 1 AUD parent had a 2.5-fold increase (AOR = 2.51; 95% CI, 2.38-2.66) and offspring of 2 AUD parents had a 4.4-fold increase (AOR = 4.44; 95% CI, 3.93-5.02) in the odds of lifetime AUD. Each additional AUD parent increased the odds of AUD in offspring in an additive pattern. Female offspring were more vulnerable to the impact of parental AUD than male offspring (OR = 1.17 in offspring of 1 AUD parent; OR = 1.48 in offspring of 2 AUD parents). Conclusions: Offspring of AUD parents had heightened odds of lifetime AUD, with an additive parental effect. Awareness of this risk can be useful for clinicians to educate individuals with AUD parents about prevention and intervention.