Background: Education level is one of the strongest protective factors against high-risk behaviors such as cigarette smoking. Minorities&rsquo / Diminished Returns (MDRs), however, suggest that the protective effects of education level tend to be weaker for racial and ethnic minority groups relative to non-Hispanic White people. Only two previous studies have shown that MDRs may also apply to lesbian, gay, and bisexual (LGB) individuals / however, these studies have focused on outcomes other than tobacco use. Aims: To compare LGB and non-LGB American adults for the effects of education level on cigarette-smoking status. Methods: Population Assessment of Tobacco and Health (PATH / 2013) entered 31,480 American adults who were either non-LGB (n = 29,303, 93.1%) or LGB (n = 2,177 / 6.9%). The independent variable was education level. The dependent variable was current established cigarette smoking. Race, ethnicity, age, gender, poverty status, employment, and region were the covariates. LGB status was the moderator. Results: Overall, individuals with higher education level (odds ratio (OR) = 0.69) had lower odds of current established smoking. We found a significant interaction between LGB status and education level suggesting that the protective effect of education level on smoking status is systemically smaller for LGB people than non-LGB individuals (OR for interaction = 1.19). Conclusions: Similar to the patterns that are shown for racial and ethnic minorities, MDRs can be observed for the effects of education level among sexual minorities. In the United States, highly educated LGB adults remain at high risk of smoking cigarettes, a risk which is disproportionate to their education level. In other terms, high education level better helps non-LGB than LGB individuals to avoid cigarette smoking. The result is a relatively high burden of tobacco use in highly educated LGB individuals.