OBJECTIVE To examine factors associated with the physical growth of breast-fed Ghanaian infants during the first 18 months of life. METHODS A community-based longitudinal study. METHODS The study was carried out in Techiman, a district capital and major food trading center in the Brong Ahafo region of Ghana. METHODS One-month old infants (n=216) with birth weight >/= 2.5 kg were recruited from Maternal and Child Health Centers. METHODS From 6 to 12 months, infants were provided with one of four types of nutritionally enhanced complementary foods. Anthropometric assessments were completed monthly from 1 to 12 months and every other month from 12 to 18 months. Information was collected on household characteristics, morbidity from common infections and dietary intakes. Blood samples were collected at 6 and 12 months to assess iron, zinc, riboflavin and vitamin A status. Multiple regression analysis was used to examine factors associated with growth during the age intervals of 1-6, 4-6, 6-12 and 12-18 months as well as size attained at 12 and 18 months. RESULTS Prevalence of diarrhea and fever were negatively associated with growth during the first year of life. No significant relationship was found between respiratory illness (defined as cough or purulent nasal discharge) and growth. With the exception of dietary zinc intake, dietary variables were generally not significantly associated with growth. Maternal education was positively associated with growth during most of the age intervals. CONCLUSIONS These findings suggest that interventions to reduce morbidity and improve the education of girls may benefit children's growth in this population. BACKGROUND Nestle Foundation; Rockefeller Foundation African Dissertation Internship Award; Fulbright Scholarship. European Journal of Clinical Nutrition (2000) 54, 41-49