Potato production is constrained by a number of biotic and abiotic factors, among which poor soil fertility is the prime one. Thus, the objectives of the study were to evaluate effect of NPSZnB plus potassium chloride rates fertilizer on growth performance, yield and yield components of potato and to determine optimum fertilizer rate and economically feasible for potato production at target Assosa areas. The experiment was laid out in RCBD with split plot arrangement with three replications. Two potato varieties, Belete and Gudane were assigned to main plot whereas six blended NPSZnB with potassium chloride fertilizers rates assigned to subplots. Totally, the experiment had twelve treatments. The interaction effects of blended NPSZnB and potassium chloride fertilizers rates not significantly (P>0.05) influenced marketable yield, unmarketable yield and total tuber yield. However, the main effects of blended NPSZnB and potassium chloride fertilizers rates were highly significantly (P<0.01) affected marketable tuber yield. The partial budget analysis was revealed that highest net benefit with acceptable marginal rate of return (1027.27%) was obtained with the application of NPK (110 kg N + 90 kg P2O5 + 69 kg K2O ha-1) fertilizers. We conclude that application of NPK (110 kg N + 90 kg P2O5 + 69 kg K2O ha-1) fertilizers were economically feasible to recommend for potato production in the study area.