A model was developed to predict the behavior of non-woven filters clogged during the filtration of nanostructured particles (i.e. agglomerates of nanometric particles). It estimates the evolution of the pressure drop and the collection efficiency during particle loading. It takes into account the filter characteristics (thickness, packing density, Davies diameter and mean fiber diameter), the particle-size distribution and the operating conditions (filtration velocity, temperature...). Only one adjustable parameter (beta(o)) is needed, which ranges from 0.7 to 1 times the ratio of the mean fiber diameter and the Davies' diameter of the clean filter. In comparison with experimental data, the model allows satisfactorily predicting the performances (pressure drop and efficiency) of several mono or dual layer fibrous filters during particle loading.