The competitive HMG-CoA reductase inhibitor lovastatin has been shown to suppress growth and induce morphological changes in a variety of non-glioma tumor cell lines. This study assesses the effects of this agent on the growth and survival of the human malignant glioma cell lines A172 and U87-MG. The response to the drug was investigated using a cell proliferation assay which revealed significant dose-dependent growth inhibition. Treatment with as little as 100 nM lovastatin over a period of 72 hours led to DNA degradation into nucleosome-sized fragments characteristic of apoptosis. Our data suggest that HMG-CoA reductase inhibitors such as lovastatin merit further investigation as potential therapeutic agents for the treatment of malignant gliomas.