One hundred and seventy four accessions of sunflower were evaluated in a randomized block design with two replications during Kharif 2010-11 at Regional Agricultural Research Station, Nandyal, Andhra Pradesh to investigate the extent of genetic variability and genetic diversity. The Analysis of variance revealed significant differences among the genotypes for all the traits indicating considerable magnitude of genetic variability of the material used for the study. Low heritability coupled with high GAM was observed for seed yield per plant due to high environmental effects and selection is effective. The genetic divergence study infers the grouping of 174 accessions in 13 clusters which indicates prevalence of good extent of diversity in the material. Cluster I had more no. of genotypes followed by clusters IV, VII and VIII. Cluster X had higher mean value for plant height and head diameter, cluster XII had higher test weight and cluster XI had high seed yield per plant. The maximum inter cluster distance was recorded between cluster XI and XII followed by cluster X and XII and clusters V and XII. Hence, it is suggested that if the diverse accessions from these diverse groups are used in the breeding programme, it is expected to produce a wide range of genetic variability in the population. The traits, 100 seed weight, plant height and days to maturity were the major causing genetic divergence among the accessions.