Two field experiments were conducted at Rice Research and Training Center (RRTC), Sakha, Kafr El-Sheikh, Egypt, in 2008 and 2009 growing seasons. The objective of this research was aimed to find out the optimum seedling age and nitrogen levels to obtain maximum production of hybrid rice varieties under normal soil. Growth analysis, grain yield and its components, N-uptake and nitrogen use efficiency were determined. The most important obtained results could be summarized as follows: In both seasons, SK2034H hybrid rice variety significantly exceeded SK2058H variety. and recorded the highest dry matter production, plant height, number of panicles/m², number of spikelets/panicle, number of filled grains (%), panicle weight, grain yield, N content, N-uptake for grains and straw and N-use efficiency (NUE). 25 day old seedlings had higher values of dry matter (DM), leaf area index (LAI), plant height, grain yield, harvest index (HI), and most of its attributes, nitrogen content, N-uptake, and use efficiency (NUE) than old seedlings 35 or 40 day old. The minimum values of these traits were obtained when plants were transplanted with 40 day old seedlings. Increasing nitrogen fertilizer levels significantly improved growth, yield and its components. Each unit increase in N-levels led to a significant increase in all these traits. Nitrogen use efficiency (NUE) was significantly higher at lower N levels and decreased significantly with increasing N fertilizer levels. On the other hand, N-content and N-uptake for grain and straw yields significantly increased by increasing the nitrogen fertilizer level up to 220 kg N/ha. The interaction between hybrid rice varieties and seedling age significantly affected dry matter, panicle weight, 1000-grain weight, grain yield and N-uptake for grains. A significant interaction effect between hybrid rice varieties and N fertilizer levels for dry matter, grain yield and N-uptake for grains. The interaction between seedling age and nitrogen levels significantly affect dry matter, number of spikelets/panicle and grain yield. It could be concluded that hybrid rice varieties must be transplanted with seedling, 25 days old, fertilized at a rate of 220 kg N/ha in three equal splits to get maximum grain yield per unit area.