Sunflower (Helianthus annuus L.) is an important oilseed crop. It was grown on more than 20 million hectares in the world in 1997, of which 60,000 ha were in Iran. There is a potential for substantial increase in sunflower acre age and production on dry land in Iran by applying optimum management practices. Two important management considerations are selecting row and plant spacings able to provide adequate plant density that will maximize seed yields and minimize seeding costs. This study conducted in 1998 investigated the effect of plant density (38,000 to 100,000 pl/ha) in combination with row (50 and 75 cm) and plant spacing (20, 25, 30, 35 cm) on agronomic traits of two open pollinated sunflower cultivars, Progress and Record, grown under rain-fed conditions at two dry land research stations, one located at Gachsaran (a warm region) and another in Sararood (a semi-cold area of Iran). Sowing was performed on moist soil after effective rains in early spring. Higher plant populations produced higher yield compared with lower populations in both locations. Average yield was higher at Gachsaran than at Sararood, this can be due to varietal differences. The rainfall during the trial year was 854.6 mm at Gachsaran and 613 mm at Sararood.