Pakistan is facing an acute shortage of edible oil. In order to overcome the prevailing situation, there is a dire need to increase per acre yield of non-conventional oilseed crops. Plant density and nitrogen fertilizer levels are among factors affecting sunflower yield and seed oil percentage. The interaction between plant spacing and N rate significantly affected seed and oil yields. In this context, the OILCROP-SUN model has been tested with sunflower and results indicated that achene yield of sunflower hybrid cultivar among various planting densities was related to their photosynthetic activity. The data suggested that there is considerable scope to exploit the yield potential of sunflower hybrid with variable planting density and nitrogen rates, depending upon the prevailing climatic conditions. It may be concluded from this study that planting density of 8.33 plants m-2band nitrogen rate N2, 125 kg ha-1 (recommended dose) is recommended for achieving high yield under agro ecological conditions of Faisalabad.