The objective of this study was to determine if weight and age at weaning affect the response of pigs to inclusion of cooked cereal in their post-weaning diet. In experiment 1, pigs (no. = 116) weaned at 17 to 28 days of age and weighing between 4 and 10 kg were individually given for 28 days post weaning, diets based on: (1) uncooked cereal or (2) cooked cereal (steamed and flaked wheat and maize). The gelatinized starch proportion was 0•265, 0•838, 0•203 and 0•745 for uncooked maize, steam flaked maize, uncooked wheat and steam flaked wheat, respectively. Pigs were offered 2•5 kg of starter diet (16•1 MJ digestible energy (DE) per kg and 17•4 g/kg of lysine). This was followed in each case by link diet (15•2 MJ DE per kg and 16•2 g/kg of lysine) to 28 days post weaning. Thereafter, pigs were grouped and given a common weaner diet and a common finisher diet to slaughter. In experiment 2, pigs (no. = 408) were weaned at between 20 and 28 days of age. Pigs were allocated by weight to heavy (7 to 8 kg), medium (6 to 7 kg) and light (5 to 6 kg) groups (24 groups of 17 pigs) and assigned to treatments as in experiment 1 for 26 days. A common weaner diet was offered between day 26 and day 56. In experiment 1, pig weight, food intake, daily gain, food conversion efficiency and carcass measurements were not affected by cooking (P > 0•05). Regression analysis indicated that weight and age at weaning had a significant association with weight at 28 days post weaning for uncooked (R2 = 0•628; P < 0•001) and cooked (R2 = 0•579; P < 0•001) cereal diets. In experiment 2, there was no interaction between weaning weight and cooking (P > 0•05) and no performance benefit resulted from cooking (P > 0•05). In conclusion, steam flaking did not improve pig performance during the treatment period or at any subsequent period.