Vertically-aligned silicon nanowires (SiNWs) are investigated for their use as thermoelectric materials. Using a silver-induced electroless-etching method, SiNWs of varying lengths are prepared, which are expected to have lower thermal conductivities as compared to bulk silicon. A thermal constants analyzer is used to perform the thermal analysis of the SiNWs, and thermal conductivity values are reduced by up to 43%. Theoretical models are then used to explain the quantitative results obtained ...