This experiment aimed at evaluating the influence of supplementing L-arginine in the diets fed to guinea fowls on growth response, haematological profile, serum biochemical indices and internal organs. A total of 300 one-day-old guinea fowl keets were allotted in a completely randomised design to three dietary treatments of basal diets (starter and grower) supplemented with 0, 0.5 and 1.0 g arginine/kg. Each treatment group was replicated four times consisting of 25 keets per replicate. At the starter phase, final weight, weight gain and feed conversion ratio (