Novel matrix composites of Na-doped Bi2Te3 with Ag nanoparticles included were prepared and studied in this article. Alloys of Bi1.2Na0.8Te3 were prepared by direct temperature melting at high temperature. Ag nanoparticles were incorporated into the system at different amounts. X-ray diffraction and scanning electron microscopy were used to examine structural, crystallographic, and morphological aspects The addition of silver caused a shift in the structure, resulting in the division of the structure into two main sections. Initially, Bi1.2Na0.8Te0.6 phase was successfully doped with Ag without any changes. Then, the phase exhibited a notable shift, due to a change in the lattice parameters, as the amount of Ag increases to x = 0.06 and 0.08 wt%. A change in the atomic order is caused by the successful replacement of Ag inside composites, which created a new structure of Bi1.2Na0.8AgxTe3. The layered bulk structure was observed by SEM investigations. Various particle sizes were observed revealing the incorporation of Ag-nanoparticles. The thermoelectric properties were studied between 273K and 473K. The four-probe approach was used to calculate electrical conductivity, and a typical differential technique was used to get the Seebeck coefficient. The Ag-incorporated Bi1.2Na0.8Te3 alloys showed quite a higher Seebeck coefficient, in comparison to the Ag-free compound. The thermoelectric power factor was calculated, and the maximum value was obtained at 30 × 102 μW/mK2 for Bi1.2Na0.8Te0.6 at room temperature. The value is quite high and encouraging for applications in thermoelectric devices. A considerable reduction in overall thermal conductivity of the studied system was observed after the addition of Ag-NPs, according to thermal conductivity studies. The lowest thermal conductivity was achieved by adding Ag-NPs at 0.08% in the Bi1.2Na0.8Te3/Ag0.08 composite. An interesting room temperature-ZT was achieved at 0.56.