The presence of easily measurable quantities of intermediate-lived fission products in ground level air during the first half of 1963 prompted an investigation of the distribution of gamma emitting nuclides in human lungs. Lungs from five cadavers were dissected, ashed and measured for 95Zr-95Nb, 13'Cs and 40K using a 4 x 4411. NaI well crystal and a multichannel analyzer. Prior measurement of the cadavers in a whole body counter using a 8 x 4-in.NaI crystal positioned over their backs, permitted calibration of a low level in situ method of measuring 95Zr-95Nb in human lungs. Counting efficiencies ran from 3 x to 6 x 10-2 counts/dis. in the full energy peak. The measured lung burdens ranged from 210 to 450 pc at the time of death and were comparable to the values expected from the ICRP model for insoluble materials. The distribution in the lobes was fairly uniform.