Abstract: Total four experiments were conducted in the different ecological zones of the province i.e. Southern, Northern and Central zones in order to find out the suitable time of earthing up for obtaining maximum yield of sunflower crop in NWFP. The average data of four locations revealed that sunflower gave highest yield if the earthing up is completed before bud formation. However, seed yield is decreased when earthing up is delayed. It is, therefore, recommended that earthing up before bud formation is necessary for obtaining higher returns from sunflower with respect to seed yield.