Increasing seed and oil yields is the top priority of most sunflower breeding programs. Getting benefit from use of heterosis is the main purpose in sunflower hybrid breeding. The objectives of this study were to determine performance of sunflower varieties and to measure the vigor of sunflower hybrids. In 2000 and 2001, sunflower hybrids were evaluated for four important yield components, yield performance, standard and regular heterosis, and heterobeltiosis, in Edirne - Turkey conditions. Based on observations in this research, seed yield of hybrids was changed between 37 and 245 kg ha-1, oil yield between 17.6 and 118.8 kg ha-1, oil content between 38.0 and 50.8% and hull rate between 19.2 and 27.1%. The highest heterosis (288.3%) and heter obeltiosis (98%) were found for oil yield. The highest standard heterosis (21.2%) was computed for seed yield. The lowest heterosis (–19.3%) and heter obeltiosis (-22.4%) were observed for hull rate. The lowest standard heterosis (-22.0%) was measured for oil yield. Regarding the studied traits, most favorable performances were shown by the 11th cross (2453-A × 2644-R). Among inbred lines, the female 2453-A and the male 2644-R exhibited higher hybrid vigor than the others.