potato is an important food crop in the highlands of Ethiopia. However, its productivity is constrained by several problems. Among these inadequate uses of N fertilizer and appropriate irrigation intervals are the most important ones. Therefore, an afield experiment was conducted in Northern Gondar Zone Debark district conducted in 2021 main irrigation season, to evaluate the effects of irrigation intervals and N fertilizer on potato yield, the treatment consisted of four rates of nitrogen (23, 46, 76, and 92 kg N ha-1) and three levels of irrigation intervals (4,7 and 10 days) and one farmer practice for comparison. Furthermore, their interaction effect on days to flower, stem number per hill, tuber diameter, plant height and tuber number per hill, marketabl e tuber yield, total tuber yield, unmarketable tuber yield, and water productivity of potato had a significant impact. When potatoes were watered using a seven-day irrigation interval and a 92 kg ha-1 N fertilizer rate, the maximum marketable tuber yields were reached. The maximum crop-water production (12.11 kgm-3) was attained when potatoes were irrigated on a seven-day interval rather than on a farmer's practice (6.55 kg m-3). According to the partial budget analysis, using 92 kg ha-1 N fertilizer with a seven-day irrigation interval yielded the highest net benefit of 603267.5-birr ha-1 and the best marginal rate of return (1813.36 %t), which can be recommended for economically and agronomically feasible potato production. Therefore, the founding of the study showed the application of 92kg N ha-1 combined with a 7days irrigation interval is recommended at Debark and similar agroecology. Further investigations may be suggested to be carried out at different seasons of the year, location, soil type, potato v arieties, and different farmer practices so as to come up with a precise and comprehensive recommendation. Key Words: Potato, Water Productivity, Irrigation Interval, N fertilizer.