The production process of oil from Elaeis guineensis palm produces an organic residual. Oil palm empty fruit bunches (OPEFB) are one of the main waste products, representing 7%. Up to now, OPEFB aren't totally used, being an environmental problem. In this paper, the employment of OPEFB pretreated with NaOH is studied as a raw material for biogas production. The pretreatment time (PT) of the OPEFB influences directly on biogas production achieving conversions of volatile solids to biogas of 96% for PT=60 min and 29 days of reaction. Biogas production is adjusted to a first order kinetic law, with kinetic constants for the generation of CH4 (0,108 d-1) and CO2 (0,107 d-1) at the reactor operating temperature (55°C). Finally, a general model is obtained to estimate volatile solids conversion to biogas as a function of pretreatment time and of the residence time inside the reactor.