This study aims to evaluate the tribological behavior of polyphthalamide (PPA) and polyetheretherketone (PEEK) lubricated with biodegradable synthetic esters. Tribological tests were performed at 23 °C and 100 °C with new and aged samples to assess the effects of increased temperature and polymer aging on friction and wear. The results of tests at room temperature and the SEM images of the wear scars show that synthetic esters provide better wear resistance to PEEK than synthetic mineral oil (polyalphaolefin, PAO). FTIR and XPS analyses suggest the formation of a physisorbed protective film by the esters. Trimethylolpropane-based ester (TMP) was shown to adsorb better to both polymers than propylene glycol-based ester (PG), but this did not translate into a better tribological performance. When compared to room temperature, tests at 100 °C showed a higher wear coefficient for both polymers, irrespective of the oil. However, the friction coefficient increased for PEEK due to a higher adhesion, while it decreased for PPA because of the material’s softening. The aging of samples at 100 °C degraded the tribological performance of the polymers, especially aging in PG ester, which caused an increase in friction for PEEK and an increase in friction and wear for PPA. PG ester was found to have caused oxidation of both polymers to a greater extent than PAO or TMP ester.