The gas phase fluorescent and triplet yields of 1,2,4,5-, 1,2,3,4-, and 1,2,3,5-tetrafluorobenzene (TFB) excited in the 2600 Å region have been determined. For 1,2,4,5-TFB, the maximum fluorescent yield (Φf = 0.338) occurs at λex = 2670 Å and the triplet yield at this wavelength = 0.515. For 1,2,3,4-TFB, the maximum fluorescent yield is 0.186 and is obtained at λex = 2645 Å; the triplet yield at this wavelength = 0.220. For 1,2,3,5-TFB the maximum fluorescent yield = 0.029 and the maximum triplet yield is 0.141, at an exciting wavelength of 2680 Å. The fluorescent and triplet yields of the three molecules, at any exciting wavelength studied, are not quenched by the addition ofcis-butene-2 (c-B-2).