Potato (Solanum tuberosum L.) is the fourth major crop of the world after rice, wheat and maize. Potato is an important crop which holds promise for food to millions of people especially in developing countries. In Ethiopia, the yield per unit area of potato is very low compared to those of other countries. There are many factors that reduce the yield of the crop among which the diseases like late blight (Phytophthora infestans) and bacterial wilt (Ralstonia (Pseudomonas) solanacearum) which play an important role. Diseases such as late blight, early blight, fusarium wilt and black leg primarily affect the crop/foliage whereas diseases such as black scurf, wart, powdery scab and common scab disfigure the tubers and reduce their market value. Major fungal and bacterial diseases affecting potato crop are reviewed here with respect to their identification, symptoms on potato plants or tubers, nature of the pathogen involved, epidemiology, control measures etc. Management of these diseases is therefore very essential. Late blight of potato can be managed using the following management (control) strategies: use of biological control agents, use of resistant varieties, intercropping, use of certified disease-free seed, use of selective fungicides and cultural practices such as destruction of cull piles by freezing or deep burying, destruction of volunteer potato plants in nearby fields throughout the season, destruction (desiccate, disc or flail and desiccate) of infected plants to avoid spread, reduction of periods of leaf wetness and high humidity within the crop canopy by appropriately timing irrigation, application of a recommended fungicide spray program (the program should start prior to the arrival of the pathogen) and desiccation of vines prior to harvest.