Monte Carlo simulations of heterogeneous systems of tin at liquid–vapour equilibrium have been performed at several temperatures from 600 to 1500 K, using a modified embedded atom model potential. Surface tension of the corresponding planar interfaces has been evaluated using the test area method. Calculation results are in good agreement with experiments presenting a maximum deviation of 10% from experiments. In addition, the Monte Carlo simulations provide a temperature coefficient (the derivative of the surface tension in regard with temperature) in reasonable agreement with the experimental coefficient.