Background: Aesthetics has a value that is not absolute and very subjective. Discoloration teeth that can interfere with aesthetics require treatment, the instance is whitening toothpaste. The amount of chemical content contained in toothpaste is considered to have an effect on health. 99% malic acid in red watermelon has been shown to whiten teeth. This research aimed to determine the difference between the use of red watermelon extract (Citrullus lanatus) toothpaste and commercial toothpaste on color changes in vitro.Methods: This research is a true experimental laboratory used 12 samples of post-extraction incisors and canines. All samples were discolored with black tea. The treatment group was divided into 3 groups, there are the group that was brushed with extract red watermelon, the group that was brushed with commercial toothpaste, and the group that was brushed with aquadest. Each group was brushed for 56 min. Measurement of color changes used shade guide and spectrophotometer was carried out before and after brushed. The results of the color changes were analyzed used One Way Annova Test and Paired T-Test.Results: The result of this research used Paired T-Test obtained that the three groups has significance value of p > 0.05 and the result used One Way Annova Test has a significance value of 0.307 (p > 0.05).Conclusion: This study showed that there was no significant difference in tooth color between using extract red watermelon, commercial toothpaste, and aquadest.