In situ dispersion polymerization of methyl methacrylate in the presence of supercritical CO2 is investigated as an alternative technique to load copaiba (Copaifera ssp.) oil in poly(methyl methacrylate) (PMMA) particles. The dispersing agent was vinyl-terminated poly(dimethyl siloxane), and the initiator was benzoyl peroxide. All reactions were carried out at 80 degrees C for 4 h under pressures ranging from 16 to 18 MPa. PMMA microparticles were characterized by gel permeation chromatography, scanning electron microscopy, gas chromatography, dynamic light scattering, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance. The obtained results indicate that spherical PMMA particles containing up to 5% w/w copaiba oil can be prepared in the reaction conditions applied in this work. Copaiba oil consists of sesquiterpenes, diterpenes, and flavonoids, which are responsible for its anti-inflammatory, antibacterial, and anticancer properties, mainly due to the presence of trans-beta-caryophyllene. A preliminary evaluation shows that in situ incorporation of copaiba oil into PMMA particles through dispersion polymerization of methyl methacrylate in supercritical CO2 is promising and may be of great interest in the pharmaceutical industry.