Industries dairy, like most other agricultural industries, generates large flows of wastewater resistant, characterized by high biological oxygen demand (BOD) and chemical oxygen demand concentrations (COD). Dairy effluent are considered a major contributor to the pollution caused by these industries. The objective of this work was to study the UASB(UpflowAnaerobicSludgeBlanket)for the treatment of dairy products and biogas effluent.The efficiency of type UASB reactors from the organic loading rate of 6 kg COD m-3 d-3 and hydraulic retention time (HRT) of 11.8 was studied and its performance was evaluated by monitoring the pH, COD, alkalinity ratio FOS / TAC and biogas production. It was observed COD removal efficiency of 71.3%. The pH of the reactor was observed between 7.0 and 7.3 and the value of FOS / TAC between 0.129 and 0.152. The average biogas production was observed in 85.8 liters per day, and the specific volume of biogas from 0.46 to 0.71 U / g COD per day. The methane content of the biogas produced, observed maximum and minimum value of 56.6% and 40.0%, respectively.