The current research presents simple synthesis, single crystal X-ray structure determination, Hirshfeld surface (HS) analysis, crystal voids studies, and density function theory (DFT) calculations of N-carbamothioylbenzamide and 1,3,5-triazinane-2,4,6-trithione co-crystal. Consequently, single crystal X-ray analysis revealed that the synthesized compounds are co-crystallized in a monoclinic crystal system with space group of P21 /c and Z = 4. HS analysis visualized, explored, and subsequently quantified intermolecular interactions present in the crystal lattices of the co-crystallized compounds. HS analysis indicated close contacts associated with molecular interactions in greater depth and augments the significance of hydrogen atom contacts in crystal packing. Similarly, void studies assessed mechanical stability, and indicated the absence of any large cavity within the packed co-crystal. Moreover, the optimized molecular structures, using DFT at B3LYP/6–311G(d,p) level, were compared with the experimentally determined ones. HOMO–LUMO energy gap was determined and the frequencies as well as the molecular electrostatic potential surface were calculated at the B3LYP/6–311 G level. The DFT computed geometry was found to be in good agreement with the crystal data geometry.