In order to teach suitable feeding and hygiene practices to a group of randomly selected Qashqa'i tribe families with 406 children aged 0–59 months, a culturally appropriate community-based education intervention approach was used. To assess the impact of the intervention on the study group, another group of families with 405 children were randomly selected to serve as the controls. At the beginning of the intervention programme both groups of children had access to a similar diet, consisting of cereals, beans, oil, sugar, milk and yoghurt. Baseline data, age, gender, weight, height and mean arm circumference (MAC), were obtained before the intervention. Using Hubley's behavioural change model, the components of which deal with beliefs, attitudes, subjective norms and enabling factors, the research team studied the behaviour of the family members and tried to change their nutritional behaviour. This was achieved by designing a suitable education programme to be carried out for 12 months. During the programme, families were instructed to follow different methods of food preparation and cooking practices. The final data were collected 3 months after the end of the intervention programme. The results indicated that the children in the study group gained: 1·16 (SD 1·2) kg body weight, 0·033 (SD 0·05) m in height, 0·0067 (SD 0·015) m in MAC, 0·8 (SD 1) in weight-for-age Z-score, 0·97 (SD 1·7) in height-for-age Z-score and 0·28 (SD 1·8) in weight-for-height Z-score by the end of the study. The corresponding values for the control group were 0·42 (SD 1·0), 0·0167 (SD 0·047), 0·0017 (SD 0·012), 0·35 (SD 1·1), 0·56 (SD 1·5) and 0·014 (SD 1·6) respectively and the differences were statistically significant (P<0·05). These findings suggest that educational interventions involving parents and/or other family members who might play a role in the care behaviour and care resources are important in feeding the children energy- and protein-enriched, hygienic, simple and cheap foods. Such practices could improve child growth even under conditions of poverty.