Tooth staining is a common problem among all ages. One of these problems can be overcome with teeth whitening procedures. Pineapple weevil contains enzymes such as bromelain and organic acids such as citric acid, malic acid and oxalic acid. This content is thought to be able to help whiten teeth that have changed color due to extrinsic factors and have a low pH, namely 3. A low pH allows the demineralization process to occur, if it continues to occur, it can increase the micro-coarseness of tooth enamel. This study aims to determine the effect of pineapple hump ethanol extract gel (Ananas comosus (L.) Merr) on the micro-coarseness of tooth enamel in the in vitro tooth whitening process. This research was conducted using a quasi-experimental laboratory method with a pre-post controlled group design. Using 30 maxillary incisors as samples, divided into 2 control groups and 4 treatment groups with concentrations of 25%, 50%, 75% and 100%. Teeth whitening using ethanol extract gel of pineapple weevil was carried out for 6 hours for 14 days. Tooth enamel micro-roughness was measured using a profilometer at the beginning and at the end of the study. The data were analyzed statistically with the dependent t-test and followed by the Kruskal Wallis test and there were significant differences between all groups (p