The effect of parity on the hematological response to supplemental hematinics and the relationship between birth weight and Hb concentration were examined in 67 pregnant rural Kelantanese Malay women recruited at 20-24 weeks of gestation. Among initially anemic women (Hb concentration at recruitment < 110 g/l), a significant supplementation effect was observed in the lower parae (3 or less children) but not in the higher parae. Among initially nonanemic women, a progressive decline in mean Hb concentration was observed in the higher parae; in the lower parae, however, an initial fall in mean Hb concentration was followed by a rise to almost the initial level. Birth weight was inversely related to initial Hb concentration. There was no association between birth weight and final measured Hb level, parity or any of the measured maternal characteristics. These observations suggest: a) women with initially lower Hb concentration might have experienced a greater acceleration of plasma volume expansion than those with initially higher Hb level; and b) hemopoiesis might be impaired in the higher multiparae.