Faba-bean (Vicia faba L.) is one of the most important legume crops cultivated in Egypt. It is liable to attack by many foliar diseases that cause severe losses in yield and quality in the crop under Egyptian conditions.The present study was carried throughout 2000 to 2011 growing seasons at three governorates (Bani-Sweif, Behera and Gharbia), on four foliar diseases (brown spot , rust , Bean Yellow Moscia virus and Leaf Curl Virus) to study the relation between climate change and disease severity for prediction of foliar diseases in future seasons. Influence of climate change on severity of faba-bean foliar diseases during growing seasons from 2000 to 2011, the highest value of diseases were recorded with the rust diseases at Bani-Sweif governorate and brown spot disease at Behera and Gharbia governorates. Forecasting of severity of diseases during growing seasons 2050s and 2100s compared with 2000s seasons in tested governorates were considerable differences of severity of brown spot during growing seasons 2050s and 2100s compared with 2000s and no considerable differences severity of rust disease and virus diseases during growing seasons 2050s and 2100s compared with seasons 2000s.