The cycles of demineralization and remineralization result in a dynamic process of caries development. Caries are prevented by the shift in the balance from demineralization to remineralization at the tooth-oral fluid interface with the help of salivary fluoride levels (in parts per million). The advantages of fluoride varnish application over other substitutes like dentifrices, mouthrinses, gels, or foams are that varnishes are well tolerated by infants, young children, or children with special healthcare needs and have prolonged therapeutic effects. This study was formulated to evaluate and compare the longevity of fluoride release from different fluoride varnishes, namely Fluor Protector, Enamelast, and Enamel Pro varnish. To evaluate and compare the longevity of fluoride release from three different fluoride varnishes. The study samples comprised 72 healthy permanent maxillary anterior teeth. The teeth were divided into four groups, with eighteen teeth in each group. The surfaces of all teeth were then covered by different colored nail varnish according to the respective group, except for a 3 × 3 mm window on the facial (labial) surface of the crown, where the test materials were applied according to their respective group. In group I, Fluor Protector varnish; in group II, Enamelast varnish; and in group III, Enamel Pro varnish was applied. Group IV was the control group; hence, no test material was applied. All specimens were then stored in plastic containers with a pH of 7.2 in artificial saliva at room temperature. The specimens were transferred into new plastic containers after 1 day, containing fresh artificial saliva, and solutions from previous plastic containers were taken for fluoride analysis. This process was repeated sequentially to analyze the amount of fluoride released in ppm from the specimens at the end of 1, 3, and 6 months. Analysis was performed on Statistical Package for the Social Sciences (SPSS) software (Windows version 22.0). Conventionally used 1.5% ammonium fluoride varnish, that is, Fluor Protector varnish, showed the least release of fluoride (0.03 ± 0.0 ppm), while resin carrier-based 5% sodium fluoride varnish, that is, Enamelast varnish showed a good amount of fluoride release for 6 months continuously, that is, (0.16 ± 0.06 ppm) at last follow-up. Enamel Pro varnish, which has 5% sodium fluoride with amorphous calcium phosphate (ACP) formula, was found to be the best varnish as it released the maximum amount of fluoride in ppm in artificial saliva for up to 3 months (0.32 ± 0.08) but less than Enamelast varnish only at 6 months follow-up that is 0.09 ± 0.03 ppm. The present study concludes that based on the amount of fluoride released for 6 months duration, Enamel Pro varnish, followed by Enamelast varnish and Fluor Protector varnish, are advisable to apply for caries prevention. Singh V, Naik S, Vashisth P, et al. Comparative Evaluation of Longevity of Fluoride Release from Three Different Fluoride Varnishes: An Observational Study. Int J Clin Pediatr Dent 2024;17(3):341-345.