Wheat kernels with visible Fusarium-damage, naturally infected, have been examined with histochemical techniques to observe mycelium growth inside kernels and change in kernels cells. Kernels infected with F. culmorum were found to be damaged more extensively, comparatively to those infected with F. graminearum, F. avenaceum and F. nivale/(Microdochium nivale). Growth of Fusarium mycelium was most abundant between pericarp and aleurone layer and alongside of scutellum. Mycelium colonized also endosperm and embryo--both plumula and radicula.