The development and documentation of a hydraulic model of the steam pipeline network at the Los Azufres geothermal field is presented, as well as the results obtained using one- and two-phase numerical simulators. Flow simulations were performed to determine pressure and heat losses, flow directions and velocities in that network. Computed well pressures agree within +/-10% with measured values, except in three of the 41 wells in the system where the differences are between 10% and 13%. Computed and measured steam flow rates entering the Los Azufres geothermal power plants agree within 10%, with the exception of one that showed a 26.7% difference. This is most likely due to a mismatch between the reported and actual flow rates delivered by the pipeline network. The computed results are considered highly satisfactory given the complexity of the Los Azufres network. (C) 2008 Elsevier Ltd. All rights reserved.