The study of 10 commercial and experimental sunflower hybrids from the Republic of Moldova and Romania, cultivated under infestation and non-infestation with Orobanche cumana, allowed us to obtain useful information regarding the impact of the pathogen on the seed production, but also their classifying according the degree of attack. The experience was carrying out in the field, during two years (2012-2013), in nine localities in Romania. Harvesting was performed at the physiological maturity stage, weighing and estimating separate seed production, according to standard methods used in research and statistical interpretation of data. The degree of orobanche infection was evaluated by assessing the frequency (F%), the intensity (I%) and the degree of attack  (G.A%). An negative correlation between the seed production of the hybrids and the infestation rate was established, but the sunflower hybrids productivity with close values of the attack degree of the parasite varies according to the locality and the year of study.