The relationship between changes in the incident rotor-blade angle due to compressor blade profile distortions and the required compressor power is investigated. This was achieved by measuring certain performance characteristics of an operational gas-turbine. Corresponding theoretical predictions were obtained from computer simulations. Graphs plotted from both the measurements and theoretical predictions were compared, and showed significant similarities. Compressor blade profile distortions from the design profile, results in significant increases in the power required by the compressor. (C) 2007 Elsevier Ltd. All rights reserved.