The influence of sodium tripolyphosphate (STPP) and zeolites on the detergency performance of linear alkylbenzene sulfonate (LAS) has been evaluated at different water magnesium ion levels. This study demonstrates that LAS/STPP gives better results in the presence of calcium than in the presence of magnesium, whereas the LAS/zeolite mixture gives better results in the presence of magnesium than in the presence of calcium.