The response of five cultivars (NH 84/457-IL, 444, 542, 443-1) of pale yellow seeded grain amaranth to varying periods of nitrogen and phosphorus fertilizer application was evaluated in a pot experiment at the National Horticultural Research Institute, Ibadan, in February, 1996. The treatment consisted of urea as the source of phosphorus. These were applied in two equal split doses at 2 and 6 weeks, 4 and 8 weeks, 6 and 10 weeks after sowing and a control (no fertilizer application) to give the cultivars of amaranth. The treatments were replicated five times and arranged in a completely randomized design. The results showed that there is a significant increase in plant height, leaf number, leaf area and dry matter production as well as the seed yield of nitrogen and phosphorus fertilized plants over the control. The cultivars 444 and 457-1L. Although cultivar 457 was superior in leaf and seed dry weight. It was inferior in seed production. The time of fertilizer application was found to be vital to the productivity of the crop, with 2 and 6 weeks split application giving superior leaf and seed yield to the other treatments. Cultivar x fertilizer interaction effect showed that cultivars 457-1L and 444 were outstanding in most of the measured plant characters.