Background: Plant extracts have been playing a useful role for centuries and are a well-established source for novel antimicrobial compounds. Studies comparing various plant extracts have shown that thyme essential oil and lemon grass oil is a potent antimicrobial agent against Candidaalbicans and thus is used for denture cleansing. Aim: To evaluate and compare the effect of various denture cleansers on flexural strength of heat cure acrylic denture base resin. Methodology: A total of 36 rectangular specimens (65 mm x 10 mm x 2.5 mm) and 32 disc shaped specimens (10 mm x 2 mm) were fabricated from heat cure denture base resin (DPI Heat Cure) for evaluation of flexural strength. The specimens immersed in distil water served as control whereas other specimens were subjected to daily cleansing with one of the three cleansers (Thyme oil 0.5%, Lemongrass oil 0.5% and Alkaline peroxide). Also, flexural strength (S) of specimens after cleansing was evaluated by subjecting the specimens to load of universal testing machine. Data analysis was done using software SPSS version 21. One way ANOVA and Post-hoc Tukey's tests were used for inferential statistics. p-value <0.05 was considered statistically significant. Results: No significant difference was seen in the mean fracture strength of the specimens immersed in thyme oil, lemon grass oil, alkaline peroxide and distill water. Conclusion: When samples were kept in distilled water as a cleansing solution, flexural strength was found to be maximum as compared to when the samples were immersed in thyme oil, lemongrass oil or alkaline peroxide solution. Statistically significant results were not obtained in any of the tested groups. No effect of time interaction was seen on the resultant flexural strength of the samples.