Background: Theobromine is a natural alkaloid of plant origin; theobroma cacao. Attempts have been made to use it as a remineralizing agent. Aim of the study: Assessment of the remineralizing potential of theobromine containing toothpastes compared to those with fluoride using scanning electron microscope. Methods: 15 maxillary first bicuspids were selected. Crowns were sectioned and immersed in a demineralizing solution for 4 days. 30 specimens were divided into 3 groups (10 specimens each); group 1, specimens brushed with toothpastes containing theobromine, group 2, specimens brushed with toothpastes containing fluoride and group 3 for specimens brushed with toothpaste free of fluoride or theobromine. The brushing time was 9 minutes and 20 seconds each. Remineralization was carried out using a pH cycling model for 3 days using artificial saliva. The enamel was scanned before and after demineralization and after remineralization. Results: A statistically significant difference was found in calcium and phosphate levels between group 1and 3 and also between group 2 and 3, however no statistical significant difference between group 1and 2. Conclusion: Theobromine could be suitable alternative to fluoride for caries prevention in terms of safety and efficiency.