In this paper, the partial enthalpy of mixing of tin and integral enthalpy of mixing (Delta(mix)(H) over bar (Sn) and Delta(mix)H) in liquid ternary Al-Ge-Sn alloys have been measured by isoperibolic calorimetry at T = (1275 +/- 5) K. It has been determined that Delta(mix)H possesses values in a range from (-3.3 to 4.1) kJ (.) mol(-1). The difference between experimental and calculated by the Bonnier model integral enthalpies of mixing is from (-0.6 to 0.7) kJ (.) mol(-1). (C) 2004 Elsevier Ltd. All rights reserved.