Sintering of cold die-pressed compacts and hot pressing have been used in order to produce high efficiency, thermoelectric epsilon-Zn4Sb3 bulk specimens. Single-phase Zn4Sb3 was successfully produced by sintering of cold die-pressed compacts using mixed elemental powders, and subsequent hot pressing produced single-phase, bulk specimens without microcracks. Phase transformations in this alloy system during synthesis were investigated using DSC, XRD and SEM. Thermoelectric properties as a function of temperature were investigated from room temperature to 600 K and compared with results of other studies. Transport properties at room temperature were evaluated. Thermoelectric properties of single phase Zn4Sb3 materials produced by the sintering of cold die-pressed compacts and hot pressing are comparable to the published data for alternate processing routes. Synthesis by sintering of cold die-pressed compacts and hot pressing offers a potential processing route to produce bulk Zn4Sb3.