Ganoderma lucidum is a rich source of unique compounds and has several properties including antifungals and contains different types of biologically active substances that are effective against different types of plant diseases. Hence, this study was conducted to assess the antimicrobial potential of G. lucidum extract. Ganoderma concentrations [5%, 10%, 15%, 20%, and 100% (pure Ganoderma extract)] were applied using the poison food technique. The different test pathogens were the following: Colletotrichum capsici, Colletotrichum gloeosporioides, Colletotrichum coccodes, Fusarium sp., Pestalotiopsis palmarum, and Alternaria solani. Results on the antimicrobial performances of Ganoderma lucidum extract against the test pathogens, the highest percentage inhibition was observed in A. solani (A6) with 46.73%. On the other hand, the purified extract (100%) of G. lucidum recorded the highest percent growth inhibition against the different test pathogens with 68.68%. Based on the effect of treatment combinations on fungus growth inhibition after incubation, the purified extract (100%) of G. lucidum recorded the highest percent growth inhibition against, C. gloeosporioides with 100% and followed by A. solani with a comparable result of 94.40%. Based on the findings, Ganoderma extracts tested (5%, 10%, 15%; 20%, and 100%) varied in the ability and persistence of their antifungal effects against the test plant pathogenic fungi. The findings of this study stipulate evidence that pure extract (100%) of Ganoderma successfully inhibited the mycelia growth of some of the test pathogens (C. gloeosporioides, A. solani, and C. capsici) which has comparable results to the Positive control (Fungide-Daconil). The antifungal activity of the different concentrations of G. lucidum variedly suppressed the growth of the plant pathogenic fungi differently.