Display omitted •New cholesteryl dithio-phosphonates of As(III) and Sb(III)•Metallolanes y metallocanes of As(III) and Sb(III) involved in a dithiophosphonate ligand.•Biological activity and DFT correlations of dithiophosphonate complexes of As(III) and Sb(III)•Crystal structure of Arsenic and Antimony dithiophosphonates into metalloheterocycles. The synthesis and characterization of six new O-cholesteryl-dithiophosphonates containing thio-metalloheterocycles of As(III) and Sb(III); (CH2S)2AsS2P(cholesteryl)(4-MeOC6H5) (2), (CH2S)2SbS2P(cholesteryl)(4-MeOC6H5) (3), O(CH2CH2S)2AsS2P(cholesteryl)(4-MeOC6H5) (4), O(CH2CH2S)2SbS2P(cholesteryl)(4-MeOC6H5) (5), S(CH2CH2S)2As S2P(cholesteryl)(4-MeOC6H5) (6), and S(CH2CH2S)2SbS2P(cholesteryl)(4-MeOC6H5) (7) are reported. 2–7 have been prepared from the reaction between the triethylammonium salt of O-3β-cholest-5-en-3-yl (4-methoxyphenyl) dithiophosphonate (1) and five and eight membered chloro-metalloheterocycles of As(III) and Sb(III). The obtained compounds have been characterized by elemental analyses, IR and NMR (1H, 13C, and 31P) spectroscopy. The 31P NMR data suggest that the dithiophosphonate ligand presents, in solution, a bidentate coordination. The structures of 3 and 4 were determined by X-ray single crystal analysis, that correspond to the first examples of such determinations in Group 15 dithiophosphonates, showing an anisobidentate coordination mode of the dithiophosphonate moiety. Sb(III) and As(III) in compounds 3 and 4 present tetracoordination and pentacoordination, respectively. The pentacoordination in 4 is achieved through a 1,5 transannular As⋯O interaction. Antibacterial assays were performed and the activity was correlated with the electronic distribution and molecular shape, employing their geometrical structures, Mulliken partial charges, dipole moments and Molecular Electrostatic Potential maps from DFT calculations.