SUMMARYApplying stochastic frontier Cobb-Douglas production function, the study assessed the efficiency of sweet potato (Ipomoea batatas) producers in the Southern region of Ethiopia. The study revealed the existence of fairly large technical inefficiency in sweet potato production. The technical efficiency ranged from 12.6 to 93.7%, with more than half of the producers above the mean efficiency level (66.1%). This suggests that there is room for output gains through technical efficiency improvement. If the average producers in the study region are to achieve the technical efficiency level of the most efficient producer in the sample (93.7%), they can realize nearly 30% output gains. The analysis of allocative efficiency also revealed that sweet potato producers were producing sweet potato with sub-optimal utilization of production inputs, suggesting that potential for output gains remains to be exploited through reconfiguration of the existing resource use. They can make more value out of their sweet potato production by reconfiguring their current utilization of production inputs in favour of more land and manure but less seed rate. Furthermore, age and education are important determinants of the efficiency of sweet potato production. In view of these findings, it is advisable to put in place appropriate extension intervention programmes that enable sweet potato producers to exploit the potential gains in sweet potato output through technical and allocative efficiency improvement. I N T RO D U C T I O NThe Southern region of Ethiopia is endowed with suitable arable land and favourable climate well suited to the production of annual and perennial crops. However, it is also the most densely populated part of the country, making horizontal expansion of arable land an unsustainable source of output growth. The importance of agricultural technologies cannot, therefore, be emphasized enough for the region. In fact, there is no more effective driver of agricultural productivity than the use of modern agricultural technologies such as improved seeds and chemical fertilizers. However, in the region, not every crop is cultivated with the application of such inputs. For example, root and tuber crops such as sweet potato are usually cultivated with little or no application of such inputs. The vast majority of sweet potato producers in the region are producing sweet potato using mainly local varieties, family labour ¶Corresponding author. and manure. As a result, they have much lower yield of 6 to 8 Mg ha −1 , although they can potentially provide over 50 to 60 Mg ha −1 (Markos and Loha, 2016). The International Potato Centre reports that average yields of sweet potatoes in subSaharan Africa are 10-times lower among smallholders than those observed among commercial producers (International Potato Centre, 2016).The challenge of increasing sweet potato output in the Southern region of Ethiopia is compounded by the fact that there is no much land left to bring under cultivation because of the high population density. In the ...