This study aimed to evaluate the effect of hydrothermal processing method on growth performance, digestive organ morphometry, activity of pancreatic amylase and lipase, plasma glucose and insulin concentration of broiler chicks fed post-hatching diets containing different carbohydrate sources (corn or sorghum). The experiment was carried out in a completely randomised design following a 2 × 2 factorial arrangement (factor 1: pelleting or extrusion processing; factor 2: corn or sorghum) with six replicates of 30 chicks each. Chicks were fed the diets in transport boxes for 24 h after hatch (post-hatch phase). After the post-hatch phase, all the chicks were housed and fed the same pre-starter diet. The response parameters were evaluated after 24 h and at seven days of age. The data were subjected to two-way ANOVA and the means compared by the Tukey post-hoc test (5%). After 24 h, chicks fed pelleted post-hatch diets showed a lower weight loss. Chicks fed diets containing sorghum had improved absorption of nutrients from yolk sac denoted by the reduced yolk sac weight. Broiler chicks fed extruded corn-based diets showed higher specific amylase activity (P < 0.001) and lower glucose concentration at 24 h after hatching (P < 0.001) while at seven days of age they showed the worst feed conversion rate (FCR) (P = 0.002). No difference on FCR was observed among the other groups (P> 0.05). Hydrothermal processing method nor carbohydrate source affected digestive organ weight of broiler chicks (P > 0.05). Broiler chicks fed extruded sorghum-based diets showed increased blood glucose levels in the post-hatch phase while the animals fed pelleted corn-based diets showed improved FCR during pre-initial phase.