Our objective was to examine differences in risk of cesarean delivery among diverse ethnic groups in New York City. Using cross-sectional New York City birth and hospitalization data from 1995 to 2003 (n = 961,381) we estimated risk ratios for ethnic groups relative to non-Hispanic whites and immigrant women relative to US-born women. Adjusting for insurance, pre-pregnancy weight, maternal age, education, parity, birthweight, gestational age, year, medical complications, and pregnancy complications, all ethnic groups except East Asian women were at an increased risk of cesarean delivery, with the highest risk among Hispanic Caribbean women [adjusted risk ratio (aRR) = 1.27, 95 % CI (confidence interval) = 1.24, 1.30] and African American women (aRR = 1.20, 95 % CI = 1.17, 1.23). Among Hispanic groups, immigrant status further increased adjusted risk of cesarean delivery; adjusted risk ratios for foreign-born women compared to US-born women of the same ethnic group were 1.27 for Mexican women (95 % CI = 1.05, 1.53), 1.23 for Hispanic Caribbean women (95 % CI = 1.20, 1.27), and 1.12 for Central/South American women (95 % CI = 1.04, 1.21). Similar patterns were found in subgroup analyses of low-risk women (term delivery and no pregnancy or medical complications) and primiparous women. We found evidence of disparities by ethnicity and nativity in cesarean delivery rates after adjusting for multiple risk factors. Efforts to reduce rates of cesarean delivery should address these disparities. Future research should explore potential explanations including hospital environment, provider bias, and patient preference.