An epidemiological study in Los Angeles showed that Chinese Americans had lower rates of depression compared to the U.S. national estimates. This study surveys the prevalence of major depressive disorder (MDD) among Asian-Americans in the primary care setting. A two-phase epidemiological survey was performed in the primary care clinic of a community health center in Boston, MA, which provides treatment to under-served Asian-Americans. Participants were Chinese Americans in the waiting area of the primary care clinic, 18 years of age or older, who spoke any one the four commonly used Chinese dialects. The Chinese version of the Beck Depression Inventory (CBDI) was used for initial screening. All consenting patients who screened positive (CBDI >/= 16) and a fraction of those who screened negative (CBDI < 16) were interviewed by a bilingual and bicultural psychiatrist with the Structured Clinical Interview for DSM-III-R, patient version, for confirmation of the diagnosis of MDD. There were 815 in the primary care clinic that were approached, of which 503 patients (62% female, mean age 50 +/- 17 years) filled out the CBDI in the initial phase of depression screening. Extrapolating the results from the SCID-P interviews, the prevalence of MDD among Asian-Americans in the primary care setting was estimated to be 19.6% +/- 0.06. MDD is common among Asian-Americans in primary care settings. The prevalence of MDD is comparable to or higher than those found in the U.S. nonminority populations.