Abundance and diversity of Pleurotus species (Oyester mushroom) and host trees for sustainable management in Ngel-Nyaki montane forest was conducted with the view to examine how abundant and diverse are Pleurotus species and their host trees in Ngel-Nyaki montane forest. A preliminary survey across the montane forest was carried out using opportunistic sampling protocol. Shannon-Weiner Diversity Index (SWDI) was used to determined Pleurotus and host trees diversity. The species richness of the Pleurotus species and host trees spotted was determined as well as species evenness. SWDI for Pleurotus species was 1.15 and that of host trees was 0.74; species richness was 0.026 and 0.0125; while species evenness was 0.248 and 0.189 respectively. The Pleurotus species observed at Ngel-Nyaki montane forest were Pleurotus pulmonarius, P. ostreatus, P. djamor and P. eryngii and Polyschias fulva, Anthonata noldeae, and Ficus lutea as host respectively. Mushroom in general including Pleurotus species serves as a source of food and income for many locals as well as urban dwellers. Pleurotus host trees play important role in the survival of Pleurotus and also function as source of fuelwood, medicine, timber, global warming fight. Government, conservation societies as well as stakeholders should sponsor training workshops for the locals on how to raise mushroom farms in order to reduce their over dependence on the wild for services of Pleurotus and host trees.