BACKGROUND: Anemia is a major global burden, and occupational gasoline exposure is a common occupational hazard factor. Although previous studies have shown that there is a potential relationship between occupational gasoline exposure and the increase of anemia prevalence, this relationship has not been fully explored. The current cohort study aimed to investigate the association between occupational exposure to gasoline and anemia, and the effect of gasoline concentration on hemoglobin (Hb) levels. METHODS: This retrospective cohort study collected baseline data from 1451 workers, including 605 exposed to gasoline and 846 not exposed to gasoline. Participants were enrolled in 2013-2015, and follow-up in 2019. Anemia was diagnosed according to WHO guidelines on hemoglobin cutoffs to define anemia in individuals and populations. Occupational exposure concentration of gasoline was measured based on the Chinese national standard (GBZ-T300.62-2017). Logistic regression was conducted to analyze the associations of occupational exposure to gasoline and anemia. RESULTS: The incidence of anemia among workers exposed to gasoline was significantly higher than that among non-exposed workers (relative risk [RR] = 11.03, 95% confidence interval [CI]: 9.45-12.53). The risks of anemia were significantly higher among participants exposed to gasoline concentrations ≥ 43.20 mg/m³ (RR = 13.92, 95%CI: 12.25-15.28), 18.01-43.19 mg/m³ (RR = 12.93, 95%CI: 11.07-14.51), and 0.01-18.00 mg/m³ (RR = 5.49, 95%CI: 3.96-7.32) compared with the control non-exposed group. The risk of anemia was significantly higher among exposed workers, after adjusting for all confounding factors. There was also a significant negative correlation between gasoline exposure concentration and hemoglobin level. CONCLUSIONS: Occupational exposure to gasoline is associated with an increased incidence of anemia, with a positive correlation between occupational gasoline exposure levels and the severity of anemia. The incidence and severity of anemia increase while hemoglobin levels decrease in line with increasing gasoline exposure concentrations. These findings emphasize the importance of assessing anemia in workers exposed to gasoline.