Docetaxel is a complex diterpene obtained from Taxus Brevifolia, and it is one of the most widely used anticancer agents. The main mechanism of citotoxic action depends on stabilization of microtubules leading to cell mitotic arrest. Independently from the schedule, the primary dose limiting toxicity of docetaxel using is neutropenia. The most common acute side effects related with docetaxel are hypersensivity reactions and dermatitis. There are also other toxicities that may be cumulative in both onset and severity; an important dose limiting side effect in patients who receive multiple cycles of the drug is fluid retention. In previous clinical trials docetaxel resulted often associated with fluid retention, even if phisiopatology of this effect is still unknown. In the majority of cases its manifestations are edema or pleural effusion. We report two cases of patients who developed repeated episodes of pericardial effusion after docetaxel infusion.