Technical Abstract: Our objective was to examine race/ethnic differences in depressive symptoms among adolescent mothers during the first four years postpartum. A prospective study of 623 adolescent mothers, 18 years or younger followed four years after delivery. Depressive symptoms were measured using the Beck Depression Inventory (BDI). These analyses focused on data collected at 3, 12, 24 and 48 months postpartum. Overall, 57% of the sample reported moderate to severe depressive (MSD) symptoms during the four-year period. The steepest increase in the percent reporting new MSD symptoms occurred during the first 12 months after delivery. The prevalence of MSD symptoms was highest at three months (36.7%) and steadily declined through 48 months (21.1%) for all race/ethnic groups with one exception: a slightly higher percentage of African-Americans reported MSD symptoms at 48 (20.0%) than at 24 months (16.9%). Logistic regression analysis used to calculate the relative odds of experiencing MSD symptoms revealed higher odds of depressive symptoms for Caucasians (adjusted odds ratio [AOR] 2.0; 95% confidence interval [CI] 1.2-3.4) at three months, and for Mexican-Americans at both 12 (AOR 2.6; 95% CI 1.4-4.8) and 24 (AOR 2.2; 95% CI 1.1-4.4) months. MSD symptoms at three months were significantly related to MSD symptoms at 48 months for all race/ethnic groups (p < .001). More than 50% of adolescent mothers experience MSD symptoms during the first postpartum year. As a group, African-American adolescent mothers appear to have the lowest rates of MSD symptoms, but higher rates of recurrence, when compared with Mexican-Americans and Caucasians.