In terms of systemic chemotherapy, the oncologist is often faced with the difficulty to discriminate between several options, at least according to evidence-based medicine. The aim of the present report was to assess to what extent the efficacy-related parameters required for the decision making process are reported in clinical trials. The analysis was restricted to lung, breast, colorectal and ovarian cancers. It included 135 phase II trials published in 1999, and 79 phase III trials published between 1991 and 2000. Response duration was mentioned in one-half and one-fourth of phases II and III trials, respectively. Only one-half of the trials reported time to progression (TTP). Finally, 28% of phase II and 44% of phase III trials reported RR, TTP and progression rates. The study indicates that the information available from reported clinical trials needs to be upgraded and homogenised in order to improve the decision making process in oncology.