There is a high competition between sunflower crop and weeds, for water, nutrients, space and light. This competition is producing losses of 20-70% in sunflower seed yield. The introducing in practice of the genotypes resistant to imidazolinone or sulfonylurea herbicides it is a revolution in sunflower crop. Sunflower resistance to herbicides it was identified in the wild sunflower Helianthus annuus, in 1998 year, in USA. Using the developed cultivated sunflower inbred lines, as sources for resistance, there have been obtained, by the genes transfer, the inbred lines with high agronomic traits, resistant to these types of herbicides. The sunflower genotypes resistant to herbicides can be used in practice, in the CLEARFIELD or Express-Sun systems. The virulence of Plasmopara halstedii, which produces downy mildew in sunflower has increased in the last period and new virulent races of this fungus appear. The parasitic plant Orobanche cumana (broomrape) is the most important biotic constraint to the production of sunflower, in all counties were this crop is grown, excepting North and South America. There is a diversity of O. cumana races, identified worldwide. The appearance of new races of this parasite has reduced considerably the available sources of resistance, in cultivated sunflower. A high level of resistance, for both, P. halstedii pathogen and O. cumana parasite was found in wild Helianthus spp. Resistance to the most virulent races of pathogen and parasite has been transferred from wild Helianthus into cultivated sunflower, by interspecific hybridization. Using the sources of resistance to this pathogen or the broomrape parasite, for the most virulent races which are now present in Europe, we have introduced genes of resistance, by using backcross or recurrent selection methods, in the best lines, which already are finished for the resistance genes transfer for herbicides or being still in process of releasing this work.