Unimolecular photodissociation of iodoalkanes in the C-3-C-8 size range is presented. The photolysis products are photoionized with coherent vacuum ultraviolet radiation and analyzed by time-of-flight mass spectrometry. With 248 nm excitation, the only primary reactions observed are those involving the C-I bond. For primary iodoalkanes, C-I bond cleavage predominates. For secondary and tertiary iodoalkanes, a competitive pathway leading to the elimination of hydrogen iodide becomes more favorable as the number of beta-hydrogen atoms increases. With 193 nm excitation primary reactions involving C-I, C-C, and in certain cases C-H bond cleavages are observed. As the molecular size increases, C-C bond cleavage occurs farther away from the C-I bond. Ground state (P-2(3/2)) excited state (P-2(1/2)) iodine atoms are produced by C-I bond cleavage at both wavelengths, but 248 nm excitation shows a much higher propensity for excited state iodine atom production. The hydrogen iodide produced by 248 nm photodissociation is internally excited since it can be photoionized with radiation 0.7 eV below the ground state ionization energy. These results are consistent with rapid, selective dissociation of the C-I bond at 248 nm which yields nonstatistical energy partitioning among the products. This selectivity persists as the molecular size increases. In contrast, excitation at 193 nm permits bond cleavage throughout the molecule and is consistent with a more random partitioning of the absorbed energy prior to dissociation.