This study evaluates the effects of nutrition education on improving knowledge, attitude, and practice (KAP) of mothers and the improvement of the nutritional status of their children. A cluster randomized controlled design using multistage sampling was employed. The integrated school‐based nutrition programme included gardening, nutrition education for parents, and supplementary feeding for children (GarNESup). KAP of mothers was assessed using pretested questionnaires administered by teachers. The randomly selected schools were randomly allocated into two groups: Both schools provided lunch to targeted children with one‐dish indigenous vegetable recipe, but School 1 received iron‐fortified rice whereas School 2 was provided ordinary rice. Eighty wasted and/or anaemic children in each school were fed for 120 days. Nutrition education for children's parents was done every school card claim day and during parent–teacher meetings using 10 developed modules. Weight, height, and haemoglobin level of children and KAP of mothers were measured at baseline and endpoint using standard techniques. KAP of mothers who had completed more than six modules had significantly increased from baseline to endpoint: Negative consequence of worm infestation (33.3% to 60.6%, P = 0.035), importance of serving breakfast for children (42.4% to 78.8%, P = 0.004), cooking vegetables (63.6% to 93.9%, P = 0.002), and purchasing fortified foods was recorded (51.5% to 93.9%, P = 0.000). Children in School 1 had significantly higher weight gain (1.33 ± 0.72) and haemoglobin level (0.49 ± 0.99) than children in School 2 (0.84 ± 0.59; 0.12 ± 0.70). Nutrition education resulted to significant increase of mother's KAP and the implementation of the integrated school‐based nutrition model significantly improved children's nutritional status.