Four organotin(IV) complexes, [(Me₂Sn)₄O₂(C₁₆H₁₇FN₃O₃)₄] (1), [Ph₂Sn(C₁₆H₁₇FN₃O₃)₂] (2), [(Me₂Sn)₄O₂(C₁₈H₁₉FN₃O₄)₄] (3), and [Ph₂Sn(C₁₈H₁₉FN₃O₄)₂] (4), have been synthesized via the reaction of R₂SnO (R = Me, and Ph) with the corresponding ligands [HL₁ = C₁₆H₁₈FN₃O₃, norfloxacin; and HL₂ = C₁₈H₂₀FN₃O₄, levofloxacin]. The four complexes were characterized via elemental analysis, FT-IR, NMR (¹H, ¹³C and ¹¹⁹Sn), as well as through single crystal X-ray diffraction analysis. Crystal structure results disclosed that complexes 1 and 3 represent tetranuclear tin monomers, which exist as a ladder-like structure containing a tetraorganodistannoxane unit and four deprotonated ligands. Complexes 2 and 4 represented mononuclear tin monomers. Further C–H⋯F non-covalent intermolecular contacts form 1D chain structures for complex 1. The C–H⋯N and N–H⋯O intermolecular contacts construct 2D planar supramolecular structures for complex 2. The C–H⋯O intermolecular contacts form 2D planar supramolecular structures and 1D chain structures for complexes 3 and 4, respectively. Furthermore, complexes 1–4 were evaluated for their in vitro cytostatic activity against the human cervical carcinoma (HeLa) cell line, the human hepatocellular carcinoma (HepG-2) cell line and normal human colon cells (NCM460). The results indicated that complexes 2 and 4 displayed a high in vitro cytostatic activity. Meanwhile, four phytopathogenic fungi were used in antifungal activity screening for complexes 2 and 4. The study confirmed that complexes 2 and 4 exhibited good antifungal activity. Furthermore, morphological and ultrastructural studies were carried out on the fungi affected by complex 2, and the results indicated that complex 2 may act on the vacuoles of cells and ultimately lead to cell death.