A convenient synthesis of highly branched melamine-formaldehyde-phenolic oligomers, which can be applied as precursors for dendritic macromolecules, is described. The synthesis comprises the condensation of methylolated melamines with phenol in the presence of stoichiometric amounts of hydrochloric acid (similarly to the Mannich's reaction conditions). A mixture of hydroxyphenylmethylmelamines was obtained of an average content corresponding to the five substituted melamine ring. NMR and mass spectrometry (LSIMS/FAB) analysis showed the products to be almost free of neat melamine-formaldehyde and phenol-formaldehyde condensates.