The structures of five triorganotin arylazobenzoates, SnR₃[O₂CC₆H₄(N₂R′)-o], have been investigated by tin-119 Móssbauer spectroscopy, and in one case by X-ray crystallography. Crystals of the compound, (4), with R = Ph and R′= 2-hydroxy-5-methylphenyl are monoclinic, space group C2/c, with a= 32.525(6), b= 9.475(5), c= 19.957(5)Å, β= 103.034(5)°, and Z= 8. The structure was solved by Patterson and Fourier methods using the intensities of 4 192 independent, non-zero reflections to a final R value of 0.0524, and comprises independent, non-interacting molecules. The carboxylato-group chelates the tin atom [Sn–O 2.070(5) and 2.463(7)Å] resulting in a distorted cis-SnC₃O₂ five co-ordinated geometry at tin. Tin-119 Móssbauer spectral data indicate that two derivatives (R = Ph, R′= 4-dimethylaminophenyl and 2-hydroxynaphthyl), have very similar structures to (4), but those of others (R = Ph, R′= 4-hydroxynaphthyl and R = C₆H₁₁, R′= 2-hydroxy-5-methylphenyl) are different. The data suggest a molecular structure for the 4-hydroxynaphthyl compound in which the tin is chelated by one carboxyl oxygen atom and a nitrogen atom with a meridional-SnC₃ON geometry, and a weakly carboxylato-bridged chain structure for the cyclohexyl compound.