Potato (Solanum tuberosum L.) is an important food security and cash crop for smallholder farmers in Ethiopia. However, the yield of potato is very low as it is produced with inappropriate fertilizer rates and types application and lack of adapted variety which are critical challenges of crop productivity. Therefore, a field experiment was conducted to identify appropriate rates of FYM and blended NPS fertilizers for optimum growth, tuber yield, and quality of potatoes during 2020/21 under irrigated condition at Arbegona District of Sidama region, Ethiopia. The treatments were consisted of five levels of integrated FYM and NPS fertilizer rates ( no fertilizer; 5 t ha -1 FYM and 75% NPS; 10 t ha -1 FYM and 50 % NPS; 15 t ha -1 FYM and 25% NPS; and 100% sole NPS ha -1 ) and three potato varieties (Belete, Gudenie and local), and laid out in RCBD in a factorial arrangement with three replications. Results revealed that combined application of FYM and NPS fertilizer significantly (P<0.05) influenced days to flowering and maturity, plant height, total and marketable tuber number, total and marketable tuber yield, dry matter content and specific gravity. The highest total tuber yield of Belete (34.53 t ha ) followed by Gudenie (33.2 t ha -1 ) over local variety (24.67t ha -1 ) were fetched with 10 t ha FYM+50% NPS fertilizer rate which were at par with the tuber yield obtained by application of full dose of NPS fertilizer alone. Thus, the supplement of 10 t ha -1 FYM with 50% NPS blended fertilizer resulted in a saving of 50% of the recommended NPS fertilizers without significantly reducing the yield obtained by applying of full dose of NPS fertilizer alone. Based on the budget analysis, application of 10 t ha -1 FYM+50% NPS fertilizer rate gave the maximum net benefit of Belete (Birr 214,277 ha -1 ) with an acceptable MRRs(1136.81%) over others. Therefore, combined application of FYM and NPS blended fertilizer at the rate of 10 t ha -1 -1 -1 FYM +50% (100 kg ha ) can be recommended for the production of potato in the study area and in the same agroecological areas. However, as this is a one seoson experiment, similar study has to be needed to repeat over multi locations of the district and same agro-ecologies to reach conclusion.