Pnictogen bonding, arguably, is one of the least explored members of the young family of sigma-hole interactions, despite the tremendous advances that have been made in “unconventional” supramolecular chemistry across recent years. One of its well documented properties is that its strength is strongly correlated with the electron withdrawing power of substituents bonding to pnictogen. Nevertheless, a practically uncharted territory is the role of structural variations that take place beyond the immediate environment of pnictogen, that is, in the region of broadly understood secondary coordination sphere. This contribution demonstrates that Sb⋯S pnictogen bonding competes, to a different degree, with Sb–S covalent bonding, depending on the extent of steric hindrance introduced by alkyl substituents (4-ethyl, 3,5-dimethyl, 4-tert-butyl), all placed at the exterior of the ligand molecules. This is observed in a set of antimony(III) diphenyldithiophosphate complexes [{(4-C2H5)C6H4O}2PS2]3Sb (4), [{3,5-(CH3)2C6H3O}2PS2]3Sb (5) and [{(4-(CH3)3C)C6H4O}2PS2]3Sb (6), as determined from single crystal X-ray crystallography. Specifically, three covalent Sb–S bonds and three non-covalent Sb⋯S pnictogen bonds are observed in 4, structure 5 exhibits one distinct non-covalent bond while 6, with bulky tert-butyl group, features no Sb⋯S pnictogen bonding. Theoretical DFT study (PB86-D3/def2-TZVP level of theory) of binding modes reveal that mixed covalent and non covalent bonding is energetically more stable (by approximately 4.5 kcal/mol) over all-covalent binding mode, providing a rationale for preferred formation of the former one in sterically less hindered structures. Alkyl bulkiness has far-reaching effect on the supramolecular organization of complex molecules themselves and on the conformation of ligand molecules within those complexes, both these aspects are explored with the use of Hirshfeld surface analysis. The most pronounced alkyl-dependent variations in intermolecular contact contributions to the HS are noted for H⋯H, C⋯H and S⋯H contacts for 3,5-dimethyl and 4-tert-butyl substitution patterns.