This book describes the biochemical and molecular characterization of RALSTONIA SOLANACEARUM associated with chilli seeds from Pakistan. This bacterium is a genetically complex organism and it has been subdivided into 5 races and 6 biovars according to host range and its utilization of different of sugars. During moon soon in Pakistan, high moisture and light intensity favor the bacterial wilt disease. The present studies were carried out to explore the chilli seeds as a potential source of aggravating this problem in the country. The isolation and initial characterization of bacterium was done on TTC and 523 media. Out of all the isolates tested, 72% showed positive hypersensitive reaction (HR) with variable response. Among these all were not confirmed to be RALSTONIA SOLANACEARUM through biochemical, pathogenicity and ELISA tests. Only 40% of these HR