Fusarium wilt of tomato is caused by a soil-borne fungal pathogen Fusarium oxysporum f. sp. lycopersici (FOL). A pot experiment was carried out to examine the effect of two antagonistic fungi namely Penecillium digitatum and P. expansum, and dry plant material (1, 2, and 3% w/w) of Chenopodium murale on histopathology of mung bean plants grown in the FOL contaminated soil. These treatments were applied to the soil either separately or in different combinations.  Transverse sections of root and stem were stained in three reagents, namely Lugol’s iodine to detect starch contents, ferric chloride to estimate phenolics, and safranine-fastgreen to detect lignin. Results showed that there were high concentrations of phenols, starch and lignin contents in root and stem sections of positive control (where only pathogen was incoulated) while concentrations of these compounds were very low in the negative control. Application of dry biomass of C. murale (DBC) and the two Penecillium spp. reduced the concentrations of these compounds to variable extents. The effect of Penecillium spp. was more pronounced than DBC. This study concludes that DBC and Penicillium spp. treated plants showed a resistance mechanism against FOL.