In the organic load removal in a wastewater treatment system, biochemical processes and hydrodynamic aspects take place as characteristicsof the flow, mix regime, residence times and reactor geometry, otherwise, the conditions for non­ideal flow as by­passing, dead zones and internal recirculation affect their performance. This study deals with an evaluation of the hydraulic behavior of a double­chamber anaerobic reactor (DCAR) of 534.5L (chamber 1=305L and chamber 2=229.5L) as a technological innovation of the UASB reactors. The DCAR was fed with Maracaibo, Venezuela municipal wastewater; each chamber was inoculated with agranular, localbrewery sludge (20% v/v). The hydraulic evaluation was performed at the liquid phase and in operation, using Li+ (LiCl) as a tracer applied in an instantaneous way at the affluent at the theoretical hydraulic retention time (TRHt) of 6 hours; 3.4 in the chamber number 1 and 2.6 in chamber number 2. The DCAR described as a plugflow in both chambers and a hydraulic efficiency close to the unit (1), indicating an almost null presence of dead zones. The CDO (CDOT) of DCAR removalefficiency was kept in the range of 59.77% to 74.46% with an average of 68.26%. For chambers 1 and 2 the average efficiency was 60.4 and 20.94 with a biogas production (L/h) of 2.768 and 0.541 respectively.