Insufficient milk is a poorly understood problem that is often identified as a major reason for early discontinuation of breastfeeding. This study explored the relationship between anemia and insufficient milk in 630 first-time mothers. The frequency of anemia (postpartum hemoglobin < 10 g/dL) was 22 percent. Anemic mothers reported a higher level of symptomatology associated with insufficient milk and were more frequently classified as having insufficient milk syndrome. Mothers with the syndrome reported a shorter period of full breastfeeding, and weaned at an earlier age. They identified not having enough milk, baby nursing too often, and baby not gaining enough weight as the main reasons for discontinuing breastfeeding, compared with baby's disinterest and conflicts with school or work as main reasons among mothers not reporting symptoms related to insufficient milk syndrome. The study results suggest that anemia is associated with the development of insufficient milk, which in turn, is related to duration of full breastfeeding and to age at weaning.