Introduction: Fluoride has the ability to incorporate into the crystalline lattice of dental hard tissues, resulting in less solubility in acidic environment.The laser–fluoridation combination is a technique that combines the application of fluoride varnish along with laser. Aim of study: This study aimed to evaluate and compare the effect of diode laser when irradiated at diffirent powers and when used either before or after fluoride varnish application on the longevity of fluoride release using ion selective electrode, from three different fluoride varnishes (in vitro study): Enamel pro varnish and Clinpro XT varnish. Material and Methods: 40 samples were collected, and then divided into 2 groups: Group Ⅰ: Enamel pro and Group Ⅱ: Clinpro XT. Each group was further subdivided into 5 subgroups, according to diode laser application, then samples were placed individually in a test tube containing artificial saliva. Fluoride release was measured by ion selective electrode for fluoride. Results: Clinpro XT had the highest amount of fluoride release. There was a statistically significant difference in fluoride release when diode laser was irradiated at 7 Watt, after Enamel pro and Clinpro XT application. Conclusion: Enamel pro and Clinpro XT can be used efficiently as fluoride varnishes. Diode laser irradiation at 7 Watt after fluoride varnish application has a profound effect on fluoride release.