An experiment was conducted at the National Horticultural Research Institute Farm Bagauda, Kadawa (11o39'N,8�02'E) in the Northern Guinea Savanna Ecological zone during 1992/93 dry season to determine the effect of varying nitrogen levels and intra-row spacing on the growth and yield of water melon (Citrullus lunatus Thumb.) under irrigation. Treatments tested consisted of three levels of nitrogen fertilizer (0,30 and 60kgN/ha) and four intra-row plant spacings, (1.0, 1.5, 2.0 and 2.5m) arranged in randomised complete block design (RCBD) and replicated three times. The results showed that increase in nitrogen levels increased the leaf number - of plant, leaf area, days to 50 percent flowering, total fruit yield per hectare, mean fruit weight and 100-seed weight. Increasing the intra-row spacing from 1.0 to 2.5m significantly increased leaf number per plant, leaf area, days to fruit maturity, fruit size, fruit (total and marketable) yield per hectare and seed weight per fruit. The highest fruit yield of 68.6t/ha was obtained from the spacing of 2.5m and nitrogen rate of 60kgN/ha.