The extraction process by steam distillation on pilot plant of essential oil from wild oregano (Lippia origanoides H.B.K) from Alto Patia region (Colombia) was studied using surface response methodology. Factors studied were the extraction time (1-3 hours), the density of the bed (60-100 g/L) and the extraction pressure (1-3 psi). The response variables were the extraction yield and the content of thymol in the essential oil. The composition of essential oils was determined by gas chromatography. Regarding yield only the bed density presented a statistically significant effect (P <0.05) and on thymol content (major component found), only the pressure factor had a significant effect (P <0.05). The optimum conditions for the extraction process obtained with the mathematical model were: time 3.7 h, bed density 113 g/L and pressure 3.7 psi, under which it is estimated that one could obtain an extraction yield of 3.4% and a thymol content of 91.9%.