A field survey was conducted to assess diseases of five important cereal crops i.e Maize, wheat, sorghum, barley and rice in parts of Western Oromia: West Shoa, Horro Guduru Wollega, East Wollega and Buno Bedele Zones during 2019 and 2020 main cropping season, covering 121 farms altogether. Prevalence, incidence and severity of each disese were scored. Diseases recorded on maize include Anthracnose (Colletotrichum sublineolum), Leaf Blight (Helminthosporium turcicum Pass), Zonate Spot (Gloeocercospora sorghi) and Loos Smut (Sporisorium sorghi). Major diseases recorded on sorghum include Anthracnose (Colletotrichum sublineolum), Leaf Blight (Helminthosporium turcicum Pass), Zonate Spot (Gloeocercospora sorghi) and Loos Smut (Sporisorium sorghi). Though many common diseases were scored on wheat, two of them - Septoria Leaf Blotches (Septoria tritici spps) and Fusarium Head Blight (Fusarium graminearum spps) appeared to be economically the most important ones. Three diseases i.e Brown spot Brown spot (Cochlidolus miyabeanus), Blast (Magnaporthe oryzae) and Bacterial Blight (Xanthomonas oryzae pv. oryzae) were recorded on rice in Chawaka district where as only net blotch appeared to be economically important for barley.