Carbides, including tellurium carbides (TeC), play crucial roles in diverse applications, but TeC synthesis has not been described in the literature. Laser ablation synthesis (LAS) coupled with mass spectrometry was used here for in situ TeC clusters synthesis and identification of the reaction products to better understand TeC formation. Laser desorption ionization time-of-flight mass spectrometry (LDI-TOFMS) was used to generate the TeC clusters and determine their stoichiometry via computer modeling of isotopic patterns. A simple one-pot procedure for Te-nanodiamonds nanocomposite preparation was developed. A suspension of fine powdered Te was mixed with a suspension of nanodiamonds (both in acetonitrile), and the resulting precipitated nanocomposite was suitable for the generation of TemCn clusters by LDI. Various unary and binary clusters were formed. The stoichiometry of the novel TemCn clusters, determined via computer modeling of isotopic patterns, is reported here for the first time. The Te-nanodiamonds composite was found to be the most suitable precursor for the generation of TemCn clusters. In total 35 binary TemCn clusters were identified, when several of them were not obtained using commercial TeC material.