['Higher rates of attrition in health research have been reported for African Americans (AAs). However, little is known about which AAs are more prone to drop out and why. One potential predictor that has not been explored is Ethnic Identity (EI). This study examined the association between EI and loss-to-follow-up among AAs enrolled in a health promotion intervention to increase fruit and vegetable intake.', 'Five hundred and sixty AA adults from two integrated health care delivery systems in Atlanta and Detroit were enrolled into a randomized intervention trial. At baseline, all participants were classified into six EI core groups: Afrocentric, Black American, Bicultural, Multicultural, Assimilated, and High Cultural Mistrust. We examined loss-to-follow-up rates by these EI type.', 'Overall, 92 participants (16%) were lost to follow up. Loss-to-follow-up rates were higher among those classified as Afrocentric (24%) than those without an Afrocentric identity (13%). After adjustment for covariates, Afrocentric participants were 1.9 times (CI: 1.1-3.6) more likely to be lost to follow up than participants without this identity type.'] Does ethnic Identity predict loss-to-follow-up in a health promotion trial?