Background: Though it can occur anywhere in the world, filaria is most common in underdeveloped nations and warm, humid climates. Controlling mosquito breeding grounds, preventing mosquito bites, and eliminating adult mosquitoes that transmit filaria are all part of the prevention of filaria. Health professionals, particularly those at the grassroots level, are essential in raising public awareness of filarial management strategies. Objectives are to assess the pretest knowledge on filarial control and preventive measures among grassroot level workers in selected areas of Deoria, to assess the effectiveness of community-based health education on knowledge regarding filarial control and preventive measures among grassroot level workers, to associate the knowledge with selected socio demographic variables. Methods: The Quantitative study was conducted utilising preexperimental one group pretest post-test design. 60 grassroot level workers were selected by purposive sampling technique. Data was collected and analysed with descriptive and inferential statistics. Results: The findings of the study indicated that, the post-test mean knowledge score was found higher than the pretest mean. Calculated ‘t’ test value was 16.33 was more than the tabulated value. Conclusion:This study revealed that health education was effective in improving knowledge regarding filarial control measures among grassroot level workers.