Abstract Crystallography reveals that the title compound, nBu₃SnL(LH) features a neutral nBu₃SnL species complexed to the neutral form of the carboxylic acid, where LH is 2-[(E)-2-(4-hydroxy-3-methylphenyl)diazen-1-yl]benzoic acid. The resulting trigonal bipyramidal coordination geometry is based on a trans-C₃O₂ donor set; O–Sn–O = 167.59(13)°. As such, a new structural motif is found for triorganotin carboxylates. In the crystal structure, two nBu₃SnL(LH) molecules self assemble via O–HO hydrogen bonding leading to the formation of 48-membered macrocyclic rings. Crystal data for C₄₀H₅₀N₄O₆Sn: triclinic, P-1, a = 11.792(7), b = 12.887(7), c = 13.708(7) Å, α = 71.61(3), β = 78.39(3), γ = 82.80(4)°, V = 1932.0(18) ų, Z = 2, R = 0.066.