We investigated the impact of maternal anaemia on birth outcomes among adolescent twin pregnancies in the United States using the vital statistics records for matched multiple births covering the years 1995-1997 inclusive. The study group consisted of mothers aged 19 years or younger who had a twin pregnancy. A cohort of women aged 20-29 years with twin pregnancies served as the comparison group. The main birth outcomes of interest were: low and very low birth weight, preterm and very preterm delivery, small-for-gestational age, stillbirth, neonatal and perinatal mortality. Crude and adjusted odds ratios for the above outcomes were calculated using the generalised estimating equation framework (GEE) that captured both intra- and intercluster sources of heterogeneity. Although not statistically significant, we detected an elevated risk for stillbirth among anaemic women (20-30%) in either age cohort, a magnitude that is substantial at the population level as well as warranting further aetiological investigations.