A one- and two-dimensional NMR study was performed on three commercial resol phenol-formaldehyde (PF) prepolymer resins. H-1, C-13, CSCM and DQF COSY NMR spectral data, in aceton-d(6), were obtained on each resin and on PF model compounds: phenol, five methylolphenols, four diphenylmethanes, two formals, two dibenzyl ethers and two dibenzylamines. Gated-decoupled C-13 experiments, using 2,4,6-trimethylphenol as internal standard, were used to quantitate the major components present in each of the three resins. The major chemical differences of the three resins were noted. A DQF COSY method was developed that allowed the qualitative identification of most of the major phenolic components present in each of the PF resins.