A survey was conducted on 1019 mothers in 79 primary health care centers in Saudi Arabia to determine the patterns of breast feeding. A large percentage of mothers (98%) had breastfed their infants at birth. This rate dropped to 96.5% during the first week of life. There were 635 (64.1%) mothers who started to breastfeed their babies within 6 hours of delivery. Over two-thirds (68.9%) of mothers gave supplemental liquids to infants during the first 3 days of their life. More than half fed their infants on demand rather than on schedule. A high proportion (94.4%) breastfed at night, with 88.1% feeding their infants more than once. There was no significant relationship between the duration of suckling and the mother's age or work status (p 0.05). However, a significant relationship (p 0.001) was found between the duration of suckling and the mother's literacy. More than three-quarters of mothers slept in the same bed with their infants or in the same room. A large percentage of women initiated breast feeding; however, many introduced a supplement too early, a practice that should be discouraged.