ABSTRACT Plant population exerts a strong influence on growth and seed yield because of its competitive effect both on the vegetative and reproductive development. For evaluating the effect of different plant populations (83,333, 66,666 and 55,555 plants ha-1) and N rates (90, 120 and 150 kg N ha-1) on sunflower hybrid (Hysun-33) a field experiment was conducted during spring seasons of 2012 and 2013 using split plot design with three replications at Agronomic Research Area, University of Agriculture, Faisalabad. Results revealed that each N increment enhances the total dry matter, achene yield and its components while oil contents were undesirably affected. During both years, total dry matter, achene yield and harvest index were detected from 83, 333 plants ha-1. Contradictorily, yield components (head diameter, number of achenes per head and 1000-achene weight) were highest in 55,555 plants ha-1 treatment. Application of 150 kg N ha-1 in 83,333 plants ha-1 plant population was best treatment to attain maximum achene yield. Keywords: correlation, nitrogen, plant population, regression, achene, sunflower, yield.