Conductance measurements are reported for iodides of tetramethylammonium (Me4NI), teraethylammonium (Et4NI), tetrapropylammonium (Pr4NI), tetrabutylammonium (Bu4NI), and tetrahexylammonium (Hex4NI), in the water+N,N-dimethylformamide (DMF) mixtures over the whole composition range, except for Me4NI and Hex4NI, where the composition range are 0-50 mol% and 50-100 mol% of DMF, respectively, at 298.15 K. The data obtained have been analyzed by the Fuoss-Justice equation, in terms of the limiting molar conductances (Δ0), the Walden products (Δ0η) and the association constant (KA). Variation in the Walden products with solvent composition are briefly discussed. The results obtained here were also compared with the literature data.