The oligomer of 4-(4-pyridylmethylideneimino)phenol was formed during oxidative polycondensation in aqueous alkaline medium using oxygen as the oxidant. Optimum conditions of the oxidative polycondensation and the main parameters of the process were found. The maximum yield of the oligomer was 52.4%. The product was characterized by elemental analysis, FT-IR spectroscopy, UV-Vis spectroscopy, and H-1 NMR spectroscopy. The molecular weight distribution was determined by size exclusion chromatography. Thermogravimetric and differential thermal analyses were carried out for 4-(4-pyridylmethylideneimino)phenol and its oligomer.