Liposomal doxorubicin (Caelyx/Doxil) has been shown to be active in around 20% of recurrent ovarian cancers. As yet, there is little clinical data on combinations of existing agents with liposomal doxorubicin, despite considerable clinical experience with soluble doxorubicin in combination. In this study, we have used an ATP-based tumor chemosensitivity assay to determine the relative efficacy of high concentrations of doxorubicin tested in combination with cisplatin, treosulfan, 5-fluorouracil (5-FU) or vinorelbine against cells obtained from recurrent ovarian tumor tissue. The results show little enhancement of the efficacy of high concentrations of doxorubicin by 5-FU, cisplatin, or treosulfan. However, vinorelbine+liposomal doxorubicin showed additive inhibition, and this combination is worthy of further testing in clinical trials.