The present invention provides a composition for the treatment of cancer including zwitterionic liposomes consisting essentially of: 50-65 mol % of a phosphatidylcholine lipid, 30-45 mol % of cholesterol, and 2-8 mol % of a PEG-lipid and cisplatin. Cisplatin is encapsulated in the liposomes in an amount such that the ratio of the total lipid weight to the cisplatin weight is from about 65:1 to about 95:1. Methods for the preparation of liposomal cisplatin and the treatment of cancer are also disclosed.