Background and objectives: Fluoride varnishes are being used to prevent caries in children. The high concentration of fluoride in varnishes apart from caries prevention may cause changes in surface properties of esthetic restorations. The study aims to evaluate and compare the effect of four commercially available fluoride varnishes with added calcium and phosphate on microhardness of three esthetic materials namely conventional GIC (Fuji II), high viscosity GIC (Fuji IX), and nanocomposite (Filtek Z350). Materials and methods: A total of 28 pellets were made of each material and stored in distilled water at 37 °C for 48 hours. The microhardness of the pellets was tested which served as a baseline. These were then randomly divided into four subgroups. In one subgroup Profluorid varnish was applied, second subgroup MI varnish was applied, third subgroup Embrace varnish was applied, and in the fourth subgroup Enamel Pro varnish was applied as per protocol. Thereafter, all the pellets were subjected to microhardness testing (load = 100 g for 15 seconds). Results: The fluoride varnishes increased the microhardness of conventional GIC (Fuji II) whereas in case of high viscosity GIC (Fuji IX) the application of varnishes reduced the microhardness. In case of nanocomposite restorative material (Filtek Z350) only Profluorid varnish increased its microhardness. Conclusion: Fluoride varnish and calcium-phosphate containing fluoride varnish effect on the microhardness of restorative material is material dependent. So, the choice of fluoride varnish with or without proprietary additives depends on the nature and composition of the restorative material.