This study aimed at assessing the potential of near-infrared reflectance spectroscopy (NIRS) for determining the distribution of soil organic matter (SOM) in particle size fractions, which has rarely been attempted. This was done on sandy soils from Burkina Faso (three sites) and Congo-Brazzaville (one site). Over the total sample set, NIRS accurately predicted carbon (C) and nitrogen (N) concentrations (g kg-1 fraction) in the fraction <20 µm. When considering Burkina Faso only, predictions were improved in general; those of C and N amounts (g kg-1 soil) became accurate for the fraction <20 µm but not for the coarser fractions, probably due to heterogeneous SOM repartition. However, most SOM being <20 µm in general, NIRS could be considered promising for determining SOM size distribution.