Abstract Metropolitan Detroit has a unique population structure, home to one of the highest concentrations of Arab Americans. Due to differences in prevalence of smoking between ethnic groups, we calculated incidence of smoking-related cancers among Arab Americans, Hispanics, non-Hispanic Whites and non-Hispanic Blacks in the metropolitan Detroit area. All first primary lung/bronchus, urinary bladder, and head and neck cancer cases diagnosed 2004-2015 were obtained from the Detroit Surveillance, Epidemiology, and End Results (SEER) Program from 2004-2015. Arab/Chaldean surname cases were identified using a validated name algorithm resulting in five different racial/ethnic categories: non-Arab non-Hispanic Whites (NANHW), non-Arab non-Hispanic Blacks (NANHB), Arab American (ArA), Hispanics, and Other Ethnicities. Frequency tables were created to analyze distribution of stage, cancer site, age group, and sex between ethnic groups. Using Integrated Public Use Microdata Series (IPUMS), population estimates for the 11-year period were generated for each ethnic group. Age-standardized incidence rates were calculated using the 2000 US Standard Million for each group of cancer sites (lung/bronchus, head/neck [HNC], and bladder) for each ethnic group. Rate ratios (RR) and 95% confidence intervals were calculated using International Association for Research on Cancer (IARC) Statistical methods for registries and NANHW as the reference group. From 2004-2015, there were 60,366 cases of smoking-related cancer reported to SEER, 1,346 of which were diagnosed in ArA. Among males, NANHB were more likely to be diagnosed with lung cancer over this time period (NANHB vs NANHW RR=1.23 95% CI (1.17, 1.30)). ArA and Hispanic males had significantly lower rates than NANHW (RR=0.81 95% CI (0.72, 0.90) and 0.66 (0.58, 0.76), respectively). NANHW, NANHB, and Hispanic males had similar HNC rates (Hispanic RR=0.84 95% CI (0.63, 1.12) and NANHB RR=1.15 (1.03, 1.29) vs NANHW). Arab males had a significantly lower rate of HNC compared to NANHW (RR=0.67 95% CI (0.53, 0.83)). NANHW and Arab males had similar rates of bladder cancer (RR=1.13 95% CI (0.98, 1.31)). NANHB and Hispanic males had significantly lower rates of bladder cancer compared to NANHW (RR=0.49 95% CI (0.45, 0.52) and 0.51 (0.43, 0.61), respectively). Similar patterns emerged among females for both lung and bladder cancers. Females also had similar rates of HNC comparing NANHW and NANHB (RR=1.09 95% CI (0.89, 1.32)), but in contrast to males, Arab women had a marginally lower rate of HNC (RR=0.75 CI (0.49, 1.17)), and Hispanic women had a significantly lower rate of HNC (RR=0.55 95% CI (0.35, 0.86)). We report previously observed differences in lung and bladder cancer and identify novel differences in HNC among subgroups in metropolitan Detroit. Our future analyses will expand to other registries in the US with significant ArA populations. Analyses should be attentive to ArA as a population subgroup, which will define research questions specific to this unique population. Citation Format: Juliana E. Fucinari, Julie J. Ruterbusch, Katie M. Zarins, Laura S. Rozek, Kendra L. Schwartz. Racial/ethnic differences in smoking-related cancers in metropolitan Detroit [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C089.