Destructive gamma-ray analysis of spent-fuel rods from the Taiwan Research Reactor has been performed at the Institute of Nuclear Energy Research. The purpose of the analysis is twofold: to identify the radioactivities, burnup values, and other essential parameters of spent-fuel rods, and to bridge the gap between the predicted and the actual values. The samples of fuel rods are taken from two kinds of irradiated materials: natural uranium metal and uranium dioxide pellets. Each sample is dissolved in nitric acid and diluted to 100 cm3; the uranium in each of these samples is identified down to the order of 10−10 g/cm3 by mass spectroscopy. A high-resolution, high-purity germanium detector coupled with a multichannel analyzer is used to detect 38 multiscaling gamma spectra within a 160-day period. Radioactivities of the evaluated fission products are compared with data from other works and with calculations using the ORIGEN-II code. Eleven of the 18 fission product values are found to be within 20% agreement with the calculated values. Deviations might be due to either an incorrect library file of cumulative fission product yields being used for the theoretical estimates, or to an overestimation of the thermal neutron flux during fuel rod irradiation. Results also indicate that although measurement of the 137Cs activity is an excellent indicator for burnup distribution, the cesium migration might lead to a misinterpretation of the data. Furthermore, the ratio of the activity of either 134Cs or 154Eu to 137Cs can eliminate the migratory effect and give a better approximation of burnup distribution along the axial direction of a spent-fuel rod.