Aim: Evaluate the prophylactic effect of Theobromine on enamel de-mineralization induced by pop candies on extracted deciduous and permanent human teeth. Methods: Twenty permanent premolars and twenty primary molars were selected. The incisal and middle thirds were coated by nail polish. Three gram of popping candy was purchased, crushed and then dissolved in 2ml of artificial saliva. Teeth were randomly divided into four groups; Group A (-ve control group): no application of pop candies nor Theobromine.Group B (+ve control group): application of pop candies only. For the two experimental groups C and D; one drop of Theobromine will be applied on tooth surface for 5 minutes in 5 days, then immersed in the artificial saliva until the next stage of the test. The two groups were exposed to pop candies solution of artificial saliva once daily for 5 min in 5 days. One drop of Theobromine was applied on the enamel surface for 2 minutes After each exposure for group D. Results: After demineralization GB, the surface of exposed enamel showed roughness texture, bright white in color. The second group GC showed the maximal changes as the surface became smoother and the enamel color almost like normal enamel. The third group GD showed average change in both surface texture and color. GC showed higher mean value than GD as, theobromine was used before and after de-mineralization. Conclusion: Theobromine is not only good re-mineralizing agent, but also it can interfere and inhibit the demineralization process and decrease mineral loss.