The temperature dependences of the density, viscosity, and electrical conductivity were investigated in four ammonium ionic liquids with the bis(trifluoromethanesulfonyl)amide anion ([Tf2N](-)). The cations for the ionic liquids were N-acetoxyethyl-N,N-dimethyl-N-ethylammonium ([N-112,N-2O2O1]) N,N-dimethyl-N-ethyl-N-methoxyethoxyethylammonium (N-112,N-2O2O1](+)), N,N-dimethyl-N-ethyl-N-pentylammonium ([N-1125](+)), and N,N-dimethyl-N-ethyl-N-heptylammonium ([N-1127](+)). Measurements were performed over the temperature range T = (273.15 to 363.15) K at atmospheric pressure. The densities were fitted to quadratic functions of temperature. The ionic liquids with the functionalized cations [N-112,N-2OCO1](+) and [N-112,N-2O2O1](+)) have the higher densities than the corresponding counterparts with the nonfunctionalized cations [N-1125](+) and [N-1127]. The viscosities and electrical conductivities were analyzed using the Litovitz and Vogel-Fulcher-Tamman equations. The ester functionalized ionic liquid, [N-112,N-2O2O1][Tf2N], has poorer transport properties (that is, higher viscosity and lower electrical conductivity) than the nonfunctionalized [N-1125][Tf2N], whereas the ether functionalized ionic liquid, [N-112,N-2O2O1] [Tf2N], has superior transport properties to its analogue, [N-1127][Tf2N]. Empirical Walden plots (double logarithmic graph of molar conductivity vs reciprocal viscosity) give straight lines with slopes less than unity.