The characteristics of oxalic acid catalyzed phenolic resins, synthesized using the conventional heating method and by one-pot microwave synthesis were evaluated and compared. Phenolic resins were produced in autoclave with reflux times of 3, 5 and 7 hours, and by one-pot microwave synthesis at different power levels (176.364, 315.092, 453.820, 592.548W) for reaction times of 15-90 minutes. UV-vis spectroscopy and GC-MS analyses showed similarities in the characteristics of the resins synthesized by both methods. Concentration of unreacted phenol in the products decreased with reaction time. For conventional method the decrease in phenol after initial 3hrs of reaction were by 4.3% (in 5hrs) and 22.3% (7hrs), while in microwave synthesis at power level 176.364W and initial reaction time of 30mins the phenol decreased by 33.05 (60mins) and 91.61% (90mins). At power level 315.092W and initial reaction time of 15mins it decreased by 36.3% (20mins), 16.5% (25mins) and 10.8% (30mins). For resins from conventional method, melting points increased with increasing reaction time 83oC, 97oC and 109oC for respectively, 3hrs, 5hrs and 7hrs, and between 95oC and 103oC for resins from microwave method at various power levels and reaction time. The FT-IR spectra analyses for the products showed strong similarity in characteristics, while the melting point data supported the GC-MS results that for conventional method mostly, the degree of polymerization depends on reaction time. Finally, closest similarities in characteristics were found between resins heated in autoclave for 7hrs and the resins made by one-pot microwave synthesis, at reduced reaction time.