Thyme oil is known for its biological activities (insecticidal, antimicrobial), but when applied freely can volatilize or be degraded. Encapsulation is a technique that allows to protect the oil and to release it gradually. Thermoplastic extrusion of starches can be used to produce biodegradable particles, in industrial scale and with low cost. The objective was to produce biodegradable carriers for controlled release of thyme oil in aqueous media. The particles were produced using single and twin extruder, without core and with 5 % of commercial oil (free and emulsified with modified starch), with corn starch (1.8, 15, 28, 45 and 71 % of amilose). The particles were characterized in relation to medium diameter, humidity content, kinect of swelling and of leaching in water (neutral pH, at 25 º C). The biological activity of free thyme oil and of the particles were evaluated against Aedes aegypti larvae and eggs. Particles showed 0.5 – 2 cm of diameter, 3 – 11 % of humidity and attained maximum swelling (80 – 350 %) in 12 – 24 h, followed by a slow leaching (1 – 16 %) of polymeric material. Both mechanisms are responsible for thymol release. Non-encapsulated thyme oil showed 53 % of thymol by gas chromatography and LC99=94 ppm (100 mL) against Aedes aegypti larvae in 24 h. The encapsulation process was efficient in keeping its biological activity and the particles with free oil and 15 % of amylose content (500 mg/100 mL) eliminated 100 % of larvae and eggs in 48 h. The way to incorporate the oil had a influence on the release and when using the emulsioned oil, the larvicidal activity was slowest (extra wall). The biodegradable particles produced with thyme oil were efficient against A. aegypti larvae and they can be applied against microorganisms too.