In recent years a few experimental and kinetic modelling studies have been devoted to the understanding of the oxidation chemistry of aldehydes, because of their importance as intermediate and product species in alkane and biofuel oxidation. In this work, new jet-stirred reactor experimental data are presented for n-butanal and n-pentanal, extending the availability of targets for kinetic model validation. Consistently with previous detailed measurements on n-hexanal oxidation, experiments have been carried out for both fuels over the temperature range 475-1100 K, at a residence time of 2 s, pressure of 106.7 kPa, inlet fuel mole fraction of 0.005 and at three equivalence ratios (í µí¼‘ = 0. 5, 1 and 2). A recently published literature model by Pelucchi et al. was used to interpret these experiments. The assumption according to which most of the Cn aldehyde reactivity is controlled by the low-temperature branching pathways of the Cn-1 alkyl radical, allows good agreement between experiments and model in terms of fuel conversion and for most of the detected species. The systematic and comparative analysis here presented for C4-C6 linear aldehydes further constrains the general rate rules, applicable to the description of higher molecular weight aldehydes, which can be produced from heavier alcohols (n-pentanol, n-hexanol etc.) and fossil fuel oxidation.