To determine the yield of colonoscopy in a predominantly Asian American gastroenterology practice in California from 8/2003 to 2/2005.A total 2,723 subjects were included: 87% were Asian and 13% were non-Asian. Advanced neoplasia prevalence was 12% in Asian men and 9% in non-Asian men (P = 0.21), and 8% and 7% in women (P = 0.62). Similar results were found in asymptomatic patients (13% and 13%, P = 0.99, for men; 8% and 6%, P = 0.46, for women). Factors associated with presence of advanced neoplasia were total number of polyps and presence of right-sided lesions. Asian men were more likely to have neoplasia overall compared with non-Asian men with odds ratio (OR) of 2.14 (1.23-3.72); however, there were no significant differences in the prevalences of advanced neoplasia in the two groups.Colorectal neoplasia is as prevalent in Asian Americans and preventive guidelines for colorectal cancer should also be advocated for this ethnic group.