Uranium/Thorium isotopic composition of 72 in situ Porites microatolls from five islands in French Polynesia. Recommendations of Dutton et al. were followed for the presentation of U/Th age data. All statistical errors are two standard deviations of the mean (2 sigma mean). All samples have been corrected for initial 230Th by using a 230Th/232Th activity ratio of 0.66 ± 0.2. Non-reported data consist of 230 Th/232 Th ratios which became negative due to background corrections. 238U Concentrations are not corrected for the background.