Growth of the A549 cell line in a perfusion system suitable for use in a magnetic resonance study has been characterized and shown to be stable physiologically and hence appropriate for serial observations. Several methods of monitoring cell growth were compared to assess the behavior of the cells in this system. Comparison between NMR metabolite data and cell growth via cell counting showed that 31P NMR signals accurately reported cell doubling time. In contrast to most NMR cell culture systems, viable cells can be recovered from the perfusion system after the NMR measurements for further biochemical studies. These data further suggest that this system will be useful for studying the physiology and biochemistry of exponentially growing cells for at least two days in NMR tube culture.