The rate of low birth weight (LBW) of Black women is more than twice that of White women. This study explores if the rate of LBW differs between Haitian and African-American women with chronic hypertension. A retrospective cohort study of all Black women self-identified as African-American (n = 12,258) or Haitian (n = 4320) delivering a singleton infant in Massachusetts between 1996 and 2000. Haitian women were more likely than African-American women to have chronic hypertension (2.7% vs. 2.1%, p = 0.006), but had similar rates of preeclampsia (3.1% vs. 3.3%, p = 0.27). The LBW rate was 10% among African-American women and 8.2% among Haitian women. After adjustment for sociodemographic, medical, and prenatal care characteristics, the greatest risks for delivering a LBW infant for Haitian women were chronic hypertension (OR = 6.8; 95% CI, 4.3, 10.6) and preeclampsia (OR = 3.2; 95% CI, 2.0, 5.1). For African-American women, the greatest risks for LBW infants were a history of delivering a LBW infant (OR = 3.9; 95% CI, 2.8, 5.4) and chronic hypertension (OR = 2.9; 95% CI, 2.1, 4.0). In a combined logistic regression model including interaction terms, chronic hypertension and preeclampsia continued to be associated with the greatest risk of LBW among all women. Differences in maternal risk factors and rates of LBW (8.2% vs. 10%) exist between Haitian and African-American women delivering infants in Massachusetts. While chronic hypertension and preeclampsia are strong risk factors for LBW for both Haitian and African-American women, unknown factors make these disorders much more potent for Haitian women.