ABSTRACT: A retrospective study was conducted to determine differences in psychosocial and medical factors among low-income women with low and normal birthweight infants. The matched sample included 65 women in each group and data was collected on medical, demographic and detailed psychosocial information. Street drug use and hospitalization during pregnancy were significantly related to low birthweight after matching for 8 factors. Psychosocial factors from a patient's past background included mother's history of drug abuse, poor parenting by her mother and father, and being abused as a child. Psychosocial factors noted during the current pregnancy were major financial concerns, street drug use; poor relationships, particularly with father of the baby; and emotional and physical abuse. Study results suggest the need for more in-depth psychosocial assessment during pregnancy, and prenatal interventions designed to address these special psychosocial factors.