Background: Whole blood bactericidal assay of Mycobacterial tuberculosis (WBA) is an assay that involves the use of pre isolated organism/tissue culture and blood from the Same patient on treatment. This assay provides a quantitative interpretation of the effectiveness of the bactericidal effect of the anti-tuberculosis medications and the host-specific immune response Aim of the study: To assess the effectiveness of treatment among patient with pulmonary tuberculosis in KNTH by using whole blood bactericidal assay (WBA) Methodology: This was a descriptive observation study. Patients with newly diagnosed pulmonary Tb presenting at KNTH, willing to be tested for HIV negative patients with the age of >18 was enrolled in the study those who has to be treated with other drugs apart from standard regimen was excluded. Prior to Tb treatment sputum was collected and culture in a liquid media. Three weeks after treatment blood was drawn and tested against pre isolated organism in a liquid culture and TTP was observed. DST results of pre isolated organisms was determined and correlated with WBA results Results: The mean WBA value among 16 patient enrolled was 1.9 (SD 0.5) for those who are using the standard regimen. Mean WBA for MDR-TB patients against blood from four patients on standard regimen was 0.92 (SD 0.03) and when tested against blood from the same patient on treatment the WBA value raised to 2.2 Conclusion: WBA is an assay which is simple and can be used to assess the effectiveness of treatment among patient on standard regimen and for those with MDR-TB strain. Recommendations: Cumulative WBA studies should be done and also WBA against MDR-TB strain and among HIV infected individual.