The applications and limitations of the more widely used methods of radiometric dating are discussed. It is concluded that because Philippine rocks are largely of Tertiary and secondarily of Cretaceous age, the dating methods most applicable are potassium/argon, fission track and uranium/ lead. Rubidium/strontium and Samarium/neodyminum methods are most applicable to Paleozoic and pre-Cambrian rocks. ¹⁴Carbon dating is applicable in the age range from about 450 to 35,000 years before present, the most effective range being between 1000 and 20,000. Under special conditions (aragonite that has not recrystallized) Uranium/Thorium can be used in the 25,000-250,000 before present range. Fission track dates can fill in a part of the gap.