Among other strategies, the use of cationic lipids as autoassembling vehicles for non viral DNA transfection has received considerable attention. An exponentially growing litterature has been published on this topic (over 700 hits for the past decade, including 400 in the last two years). The present review focuses on the main present strategies aiming at improving cationic lipids induced transfection, and on some of the frequently encountered problems that should be solved to apply these non-viral vectors for human health. The review contains several sections dealing with the chemistry, physico-chemistry, cell biology, in vivo biology, and targeting of cationic-lipid DNA complexes.