In this review, the different types of liposome used in medicine, in particular in the field of antitumor therapy, are focalised, emphasizing their structures, pharmacological action, pharmacokinetics and biodistribution, toxicity profiles and in the main clinical applications. The first-generation liposomes (conventional liposomes) comprised a liposome-containing amphotericin B, Ambisome, and Myocet, doxorubicin-containing liposome used in clinical trials to treat metastatic breast cancer. The last generation liposomes were pegylated liposomal doxorubicin (Caelix), called "stealth liposomes" because of their ability to evade interception by the immune system, characterized by very long-circulation half-life, favourable pharmacokinetic behaviour and specific accumulation in tumor tissues.