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This contribution describes the synthesis and structural investigation of the symmetric and non-symmetric oxamides N,N ′-bis(2-hydroxyphenyl)oxamide 1, N,N ′-bis(5-tert-butyl-2-hydroxyphenyl)oxamide 2, N,N ′-bis(3,5-dimethyl-2-hydroxyphenyl)oxamide 3, N,N ′-bis(2-hydroxybenzyl)oxamide 4, N,N ′-diphenethyloxamide 5, N-(2-hydroxyphenyl)-N ′-(2-methoxyphenyl)oxamide 6, N-(2-hydroxyphenyl)-N ′-phenethyloxamide 7, (1S,2R)-(–)-N-(2-hydroxyphenylcarbamoylcarbonyl)norephedrine 8, (1R,2S )-(–)-N-(2-hydroxyphenylcarbamoylcarbonyl) 9, ethyl N-(2-hydroxyphenyl)oxalamate 10 and ethyl N-(2-methoxyphenyl)oxalamate 11. The structures were established by 1H, 13C, 15N and variable temperature NMR spectroscopy. Compounds 1–4 and 6–11 are stabilized by intramolecular three-center hydrogen bonding between the amide proton and two oxygen atoms. The 1H NMR Δδ/ΔT value of the amide proton correlates with the 15N NMR chemical shift. The X-ray diffraction molecular structures of 1 and 11 showed a planar conformation with trans configuration in the solid state, corresponding to the preferred conformation found in solution.