The partial for aluminium and integral enthalpies of mixing in liquid Al-Fe-Si alloys have been measured by high-temperature isoperibolic calorimetry at 1750 +/- 5 K. The study has been performed along five sections with constant concentration ratios of Si and Fe. The integral enthalpies of mixing were simulated according Bonnier geometry. The differences between experimental and simulated data possess negative values within the experimental errors range, which may testify that ternary interaction is negligibly small at the experimental temperature. (C) 2003 Elsevier B.V. All rights reserved.