We have determined the element effect of halogens for nucleophilic aromatic photosubstitutions. Irradiation of 4-nitroanisole and 2-halo-4-nitroanisoles (halogen = F, Cl, Br, I) in 1:2 acetonitrile:water containing hydroxide ion or pyridine causes mainly displacement of halogen when it is present. Pyridine exclusively displaces the halide when present, and hydroxide ion does major displacement of halide and minor displacement of the nitro and methoxy groups. We have determined the product distributions from these reactions, the Stern-Volmer plots for dependence of reciprocal quantum yield on reciprocal nucleophile concentration, the triplet lifetime and quantum yield of intersystem crossing of each of the nitrophenyl ethers. The rate constants for substitution by hydroxide ion and pyridine on the triplets at the various ring positions are calculated from these data. The reactions are very fast. The rate constant for substitution by hydroxide ion at the fluoro position of triplet 2-fluoro-4-nitroanisole is 1.4 x 109 M-1 sec-1 while that of pyridine is 6.3 x 108 M-1 sec-1. Both nucleophiles quench the excited state competitive with substitution. The relative rates for substitution on the halogen-bearing carbon (F: Cl: Br:I) are 30:2.7:2.4:1 for hydroxide ion, and 10:11:9:1 for pyridine, respectively. These numbers, especially for pyridine, require adjustment for the partitioning of the sigma complex in order to give attack rate constants. They are inverse to halogen element effects in SN2 and E2 mechanisms and parallel to the element effect for ground state nucleophilic aromatic substitutions by comparable nucleophiles. This implies direct formation of a sigma complex from the triplet.