Background: Dental plaque (biofilm) is a well-known contributor to the onset and progression of many dental illnesses. Plaque is a natural biofilm that develops on oral surfaces and contains a wide variety of organisms. As a result, it is critical to control plaque formation, particularly in the young population, by implementing effective preventive strategies. Objective: To assess and compare plaque removal efficacy of water flosser and string floss in patients. Study design: Randomized controlled trial Place and Duration of study: Department of Periodontology, Sardar Begum Dental College, Gandhara University from 1st March 2019 to 31st May 2019. Methodology: Seventy patients were enrolled. Patients were randomly allocated to one of two groups, group A (using dental floss) as the control group and group B (using waterpik) as the intervention group, using the lottery technique. Patients were randomly allocated to one of two groups, group A (control group), using dental floss and group B (intervention group), using waterpik utilizing the lottery technique. All participants were taught correct brushing technique utilizing the Modified Bass technique and manufacturer's instructions for using waterpik as well as normal flossing instructions for using Dental floss. Results: The mean age presentation was 34.23±6.78 years. The females were 42 (60%) males were 28 (40%). The mean percentage showed that those using water flosser with tooth brushing had low plaque score than using string floss with tooth brushing. The independent t test showed that water flosser is significantly more effective (p=0.001) in plaque reduction than conventional string floss. Conclusion: A water flosser coupled with hand brushing is more effective in eliminating plaque than string floss. Plaque removal was 20-30% higher in the group that used a water flosser. Key words: Efficacy, Dental floss, Water jet