Ethiopia is a country with a total population of more than 110 million, of which about 80% of the total population is engaged in subsistence farming in rural areas. Although agricultural sector plays a great role in Ethiopian economy, it is characterized by low productivity due to technological and socioeconomic factors. Improving smallholder irrigated tomato production, and productivity, would contribute to enhancing food security and alleviating poverty. Therefore, this study was investigated to fill this gap with the aim of analyzing technical efficiency of irrigated tomato production and its determinant factors in North Gondar Zone, Amhara Regional State, Ethiopia. Primary data were collected from 160 farmers’ selected using multistage sampling procedure and analyzed using descriptive statistics, a parametric stochastic frontier production function models. The stochastic frontier and Cobb-Douglas functional form with a one-step approach was employed to analyze efficiency and factors affecting efficiency in irrigated tomato production. The estimated gamma parameters indicated that 80% of the total variation in tomato output was due to technical inefficiency. The means technical efficiency was found 55%, and about 6,907.32 kg of tomato output per hectare was lost due to inefficiency factors implying there is a room for improvement in technical efficiency by 43% with the present technology. The Stochastic Production Frontier (SPF) result revealed that ODE, DAP and plot size at 1% and labor at 10% probability level significantly influencing tomato production. The socio-economic variables that exercised important role for variations in technical efficiency positively were the level of education, TLU and watering in morning, and in contrast age, off farm, watering frequency and training for marketing were found to increase inefficiency significantly among farm households. To get better farmers' efficiency in the production of irrigated tomato a continuous marketing training should be established and strengthening the available farmers training center (FTC) to improve farm productivity. The government and any concerned bodies should be build irrigation canals and other alternatives so as to reduce watering frequency. There should be timely and sufficient supply of DAP to improve farmers’ efficiency in production of tomato.