Anthropometric status and growth patterns were investigated in 398 infants born in 1994 in five low income communities in Ontario, as a part of the longitudinal, prevention initiative, 'Better Beginnings', 'Better Futures'. Seventy-four percent of families lived below the poverty line. Breastfeeding initiation rate was 76.3% and 38.9% of those infants were breastfed for >=4 months. Demonstration sites had lower maternal education and higher rates of formula feeding. Growth appeared adequate; the proportion of infants >95th percentile of the NCHS reference data for weight-for-age, length-for-age and weight-for-length and head circumference was 13%, 12%, 11% and 14 respectively. Growth patterns differed between infant feeding modes and comparison and demonstration sites. Formula fed infants demonstrated greater gains in weight. Exclusively breastfed infants had the smallest weight gains from birth to 18 months. Mothers need to be apprised of these differences in infant growth to encourage longer durations of breastfeeding.