Objectives. We used data gathered from 6259 youths between the ages of 13 and 23 years to compare trends in smoking among 4 racial/ethnic groups. Methods. We weighted trend data to represnet baseline respondent characteristics and evaluated these data with linear contrasts derived from multiple regression analyses. Results. Although African Americans exhibited higher initiation rates than Whites, they exhibited consistently lower rates of regular smoking than both Whites and Hispanics. This seeming anomaly was explained by African Americans' lower rates of transition to regular smoking and greater tendency to quit. Racial/ethnic disparities were accounted for by differences in pro-smoking influences. Conclusions. Reducing racial/ethnic disparities in smoking may require reducing differences in the psychosocial factors that encourage smoking.