Potato is ranked third after rice and wheat in terms of consumption in the world, and first among root and tuber crops. However, the production is limited by several factors including low in soil fertility, lack of improved varieties, inappropriate spacing, and other poor agronomic management. The objective of the present study is to recognize the optimum rate of the blended NPSZnB and potassium fertilizers for profitable production of potato at Assosa area. The experiment was laid out in RCBD with arrangement of split plot in three replications. The main plot consisted of two potato varieties i.e. Belete and Gudane varieties. The subplot consisted of four levels of blended NPSZnB with potassium chloride rates, one recommended NPK (nitrogen, phosphorus and potassium) and unfertilized plot. The interaction effects of potato tuber size distribution and quality traits were not significantly (P>0.05) affected by different rates of NPSZnB with adjusted nitrogen, phosphorus and potassium chloride fertilizers and different potato varieties. Out of different potato varieties, Belete variety gave the highest yield as compared to Gudane variety. The highest total tuber yield and large sized tuber yield were obtained by the application of 200% NPSZnB (35.4N+70.6P<sub>2</sub>O<sub>5</sub>+15.2S+0.5B+4.4Zn) +138 kg<sub> </sub>K<sub>2</sub>O ha<sup>-1</sup>, with adjusted 184.6kg N+ 109.6kg P<sub>2</sub>O<sub>5 </sub>per ha therefore, we are tentatively recommended for beneficiaries at Assosa area.