This study estimated the profitability and the level of technical efficiency of the onion farms. It also identified factors that contribute to technical efficiency in onion production. Data were collected from 180 randomly selected onion farms using a pretested interview schedule. Partial budgeting techniques and the stochastic production frontier were modeled for data analysis. Profitability indices revealed a value of 0.771 and 0.280 for operating ratio and return to capital invested respectively. The mean technical efficiency score for the farms was 88.35%. Quantities of water and onion seedlings, farm size, household size, and farming experience significantly affected the technical efficiency of the farms. The study concluded that onion production was profitable in the study area.  The government should look into the possibility of providing an alternative source of irrigation for the farmers to conserve water and lower the cost of irrigation.