Colloidal suspensions of PbTe nanoparticles coated with oleic acid (OA) were obtained using a high-temperature solution phase (HTSP) method. Both diphenyl ether and squalane were used as high-boiling heat-transfer agents. It was shown that the change in standard synthesis conditions, such as the temperature of reaction and the group IV/group VI precursor molar ratio, led to precipitation of the nanocrystalline tellurium in parallel with PbTe nanoparticles. Bonding between the oleic acid and nanoparticles (NP) was investigated using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results indicated that oleic acid coordinated the nanoparticles symmetrically through carboxyl groups, and the interaction modes were bridging bidentate and chelating interactions. The strong coordination by the capping monolayer made the NP stable against oxidation. In contrast to bulk, nanocrystalline PbTe possesses photosensitivity to IR radiation at low temperatures enabling electrical conductivity, which itself has an activation character with rising temperature.