Plants belonging to the genus Maytenus are members of the Celastraceae family. They have been widely used by different peoples as treatment for curing many diseases. The aim of this study was to explore the anti-inflammatory and antioxidant properties of Maytenus elaeodendroides stem bark extracts, an endemic Cuban plant. The antioxidant activity of four extracts (EtOH, EtOAc, n-BuOH, and diethyl ether/petroleum ether 1:1) was determined using DPPH and FRAP methods. Meanwhile, anti-inflammatory effects by the edema method were induced by croton oil in the mouse ear. The investigated extracts showed radical reduction capacity and prevented ear inflammation at doses of 4 mg/ear. In addition, FIA/ESI/IT/MSn was used to determine the qualitative chemical composition of the EtOAc extract and allowed the identification of five flavan-3-ol monomers, four dimers, and other proanthocyanidin oligomers. From this extract three flavan-3-ol compounds (elaeocyanidin and 4′-O-methylgallocatechin), one of them new (2′-hydroxy-4′-methoxy-epigallocatechin), and a proanthocyanidin dimer (afzelechin-(4β→8)-4′-O-methylepigallocatechin) were isolated and identified by the chromatographic method and spectroscopic techniques, mainly ESI-MS and NMR spectroscopic methods.