Pb205 has been produced by the Pb204(n, γ)Pb205 reaction in the Materials Testing Reactor. The Pb205/Pb204 atom ratios of 0.001175+/-0.000060 and 0.005064+/-0.000063, respectively, were measured in a mass spectrometer for lead samples irradiated in the MTR for approximately 3 months and 1 year. The neutron capture cross section of Pb204 for MTR neutrons is 0.7+/-0.2 barn. The partial half-life of Pb205 for L-electron capture is (3.0+/-0.5)×107 years. The KL electron capture ratio of Pb205 is <=6×10-4, and the disintegration energy is probably less than 86 kev. No gamma rays were observed in the decay of Pb205.