In order to study the response of two yellow maize hybrids i.e. SC 173 and TWC 352 to three irrigation intervals i.e. 12, 16 and 20 days and four nitrogen fertilizer levels i.e. 0, 45, 90 and 135 kg N/fad. The present investigation was carried out during two successive seasons of summer 2011 and 2012 at the Agriculture Research Station, Faculty of Agric., ZagazigUniv., Ghazala Location, Sharkia Governorate, Egypt. The combined analysis indicated that all growth characters as well as grain yield and its attributes except number of rows/ear and shelling percentage were significantly decreased when irrigation interval was prolonged from 12 or 16 days to 20 days. It was found that SC 173 surpassed TWC 352 in all growth characters, grain yield and its attributes except, number of ears/ plant, number of rows/ear and shelling percentage. On the other direction, TWC 352 surpassed SC 173 in ear diameter. Respecting to the influence of nitrogen fertilizer levels, the results indicated that ear length, ear diameter, 100-kernel weight, kernel weight/ear and grain yield/fad were significantly increased with each increase in nitrogen fertilizer level up to 135 kg N/fad. Whereas, plant height, chlorophyll content and number of kernels/row were significantly increased by raising nitrogen fertilizer level up to 90 kg N/fad while, number of ears/plant was responded only up to application of 45 kg N/fad. The results of interaction between the studied factors recorded significant increase in kernel weight/ear and grain yield/fad due to increasing nitrogen fertilizer level up to 135 kg N/fad under irrigation intervals of 12 or 16 days. In addition, SC 173 presented good response for N fertilizer up to 135 kg than TWC 352 in 100-kernel weight, kernel weight/ear and grain yield/fad. It could be recommended that irrigation of SC 173 hybrid at 16 days intervals with adding 135 kg N/fad maximized grain yield per unit area under clay soil condition of Sharkia Governorate, Egypt.