Background The relationship between African-American women's upward economic mobility and small for gestational age (weight for gestational < 10th percentile, SGA) rates is incompletely understood. Objective To ascertain the extent to which African-American women's upward economic mobility from early-life impoverishment is coupled with reduced SGA rates. Methods Stratified and multilevel logistic regression analyses were completed on the Illinois transgenerational dataset of African-American infants (1989-1991) and their Chicago-born mothers (1956-1976) with linked U.S. census income information. Results Impoverished-born (defined as lowest quartile of neighborhood income distribution) African-American women (n = 4891) who remained impoverished by the time of delivery had a SGA rate of 19.7%. Individuals who achieved low (n = 5827), modest (n = 2254), or high (n = 732) upward economic mobility by adulthood had lower SGA rates of 17.2, 14.8, and 13.7%, respectively; RR = 0.9 (0.8-0.9), 0.8 (0.7-0.8), and 0.7 (0.6-0.8), respectively. In adjusted (controlling for traditional individual-level risk factors) multilevel regression models, there was a decreasing linear trend in SGA rates with increasing levels of upward economic mobility; the adjusted RR of SGA birth for impoverished-born African-American women who experienced low, modest, of high (compared to no) upward mobility equaled 0.95 (0.91, 0.99), 0.90 (0.83, 0.98), and 0.86 (0.75, 0.98), respectively, p < 0.05. Conclusions African-American women's upward economic mobility from early-life residence in poor urban communities is associated with lower SGA rates independent of adulthood risk status.