A standardized questionnaire was administered to 65 mothers attending the Nutrition Clinic of the Ahmadu Bellow University Teaching Hospital, Kaduna, Northern Nigeria, over the October-December 1978 period to determine at what age the 1st supplementary diet was introduced, the age the child was weaned, and the weaning practices. The questionnaire dealt with various aspects of weaning knowledge, attitudes, and practices. The mothers were referred to the Nutrition Clinic because their babies already were suffering from protein energy malnutrition, had failed to thrive, or had severe infections, e.g., measles, gastroenteritis, or respiratory diseases. 58 (89.2%) of the families were of low socioeconomic status. 36 mothers (55.4%) introduced supplementary feeds to their babies between 4-6 months of life; 27 (41.5%) mothers introduced supplementary feeds when their children were between 7-9 months. All the mothers used corn, guinea corn, or millet gruel. A decision to wean a child may be made if the child can crawl, walk, or has a good set of erupted milk teeth, even if the child has not reached the traditional weaning age of 20-24 months. The mean age of weaning was 17 months in this study. 51 (78.5%) of the mothers responded to the question about weaning food taboos, prohibitions, and their reasons during the weaning period. Even when protein is available, a child may be denied the protein because of sociocultural factors. The use of carbohydrate gruels among these low socioeconomic families coupled with sociocultural factors compounded the feeding problem, and, consequently, protein energy malnutrition was common during the weaning period.