ABSTRACT. Objective: Individuals' perceptions of drinking acceptability in their society (perceived injunctive drinking norms) are widely assumed to explain ethnic group differences in drinking and alcohol use disorders (AUDs), but this has never been formally tested. Immigrants to Israel from the former Soviet Union (FSU) are more likely to drink and report AUD symptoms than other Israelis. We tested perceived drinking norms as a mediator of differences between FSU immigrants and other Israelis in drinking and AUDs. Method: Adult household residents (N = 1,349) selected from the Israeli population register were assessed with a structured interview measuring drinking, AUD symptoms, and perceived drinking norms. Regression analyses were used to produce odds ratios (OR) and risk ratios (RR) and 95% confi dence intervals (CI) to test differences between FSU immigrants and other Israelis on binary and graded outcomes. , and perceive more permissive drinking norms (p < .0001). For all four drinking variables, the FSU group effect was at least partially mediated by perceived drinking norms. Conclusions: This is the fi rst demonstration that drinking norms mediate ethnic differences in AUDs. This work contributes to understanding ethnic group differences in drinking and AUDs, potentially informing etiologic research and public policy aimed at reducing alcohol-related harm. (J. Stud. Alcohol Drugs, 73, 981-990, 2012)