Abstract The surface tension and liquid-gas density profile through the interface of one- and two- component Lennard-Jones fluids were calculated using Molecular Dynamics simulation techniques. The system size, film thickness, interface area, intermolecular potential cut-off, composition, and temperature were varied. For the one-component system, the results were compared to previous work and some discrepancies of the past work were resolved. By combining this work with correct results from previous authors, the minimum system size, film thickness, equilibration time, and the trade-off between cut-off and computer time were determined. Using configurations calculated for moderate cut-offs, the surface tension was extrapolated to the full potential value by using a tail correction and the results compared to simulations performed with the longer cut-offs. The results showed the possibility of obtaining estimates of the surface tension for large cut-off simulations from moderate cut-off simulations provided that the density profile does not change significantly with increase in cut-off. Using the criterion for equilibration determined from the one-component systems, two-component systems at varying compositions and temperatures were simulated and the tail correction applied.