This review centers on the role of nematode and fungi in plant diseases and their interactions on disease complex. Fungi attack plants at all stages of its development resulting into rust, mildew, leaf spot and chlorosis that led to the death of its host while nematodes reduce plant growth and yield efficiency due to their feeding habit on host plants.Parasitic nematodes causes wounds to their host plant either by simple micro - puncture or by rupturing on the roots and is important in predisposing plants to fungi infection through the creation of more infection sites. Nematode attacks lowers the resistances of plants to diseases caused by other organism and create new plant pathogenic fungi with an increase in the pathogenicity of other microorganisms. The role of fungi is related to the behavior of fungal pathogens in a dormant or active state under changed conditions created through infection of the host plant by parasitic nematode. Fungi / nematode interaction in disease complex results into major consequences in increased early plant mortality in the growing season and also resistance to fusarium wilt symptoms were more severe, developed more rapidly with greater frequency when infected by nematode. The role of fungi in the interactions with nematode is not delineation because a synergistic relationship, the common feature of fungus / nematode interaction and diseases caused by fungal pathogen become more pronounced and may appear earlier when plants are infected with nematodes.