Olive growing areas in Tekirdag, Canakkale, Balikesir, Bursa, and Yalova cities of Marmara region were visited and prevalence and incidence of olive knot disease were noted. Disease prevalence was recorded as 100, 81, 66, 4 and 0% in Canakkale, Balikesir, Tekirdag, Bursa and Yalova, respectively. Disease incidence was 73, 56, 30 and 0.6% in Canakkale, Balikesir, Tekirdag and Bursa, respectively. Totaly 208 bacterial strains which showed positive hypersensitive reaction on tobacco leaves were isolated from 104 diseased plants on King's medium B and PVF1 medium from Marmara region. Pathogenicity tests were performed with selected 38 strains and a reference strain (CFPB 1672). All strains were pathogenic on olive plants cv Edremit. Eighty eight strains were re-isolated and used in identification tests. All strains were gram negative, oxidase negative, pectolytic activity negative, levan negative, and arginin dehydrolase negative, but hypersensitive reaction on tobacco leaves was positive. The identification of the strains was confirmed by BIOLOG, spesific-PCR and microbial identification system (MIS) based on whole cell fatty acids. Pseudomonas savastanoi pv. savastanoi strains showed phenotypic similarity as a ratio of 96.7% by whole cell fatty acid compositions. The strains were genotypically similar as a ratio of 97.4% by polymorphism in BOX-PCR.