Verticillium dahliae (Kleb) is a major sunflower disease (Helianthus annuus L.) in Argentina. The aim of this study was to evaluate different lines of EEA Pergamino sunflower breeding program for Verticillium reaction in order to find effective sources of Verticillium resistance. A method of seedling inoculation was applied to evaluate the performance of 689 lines. The scale was R (resistant), MR (medium resistant), MS (medium susceptible), AS (highly susceptible). The lines were grouped according to genetic background and percentages of lines in each class were calculated. The major variability was detected in P4. A higher percentage of resist ance was obtained in selfed populations than in crosses of different lines. The crosses of local × exotic lines had better performance than the respective groups. Variability for Verticillium resistance was obtained in different sources of germplasm.