Physiochemical pretreatment of landfill leachate using coagulation was examined and found to be an effective means of reducing turbidity, suspended solids, metals and dispersed oil. Lime was found to be the most effective pretreatment coagulant for treating the landfill leachate examined in this study. A 6.0 g/1 dosage resulted in 98% reduction in turbidity. Reductions in dispersed oil were substantial and were accompanied by small removals of dissolved organic matter. Additionally, many heavy metal species were successfully removed. Polyelectrolyte coagulant aids were found to be useful in increasing the rate of turbidity reduction. Re‐carbonation is suggested, to lower the pH to a range desirable for successive treatment processes.