A retrospective review of data on patients entered on two limited small cell lung cancer studies of the National Cancer Institute of Canada (BR.3 and BR.6) was undertaken to determine the value of restaging and rebronchoscopy in responding patients. An economic evaluation was also done. Repeat scans (brain, liver) and bronchoscopy were carried out in 190 patients and 5 (2.6 percent) were positive, despite other evidence suggesting response. One hundred thirty-nine of 324 patients who achieved complete response on the two trials underwent rebronchoscopy. Among these, 122 (87.7 percent) were negative and eight (5.8 percent) were inconclusive. Nine (6.5 percent) were positive despite other evidence suggesting the patient had achieved a complete response. A small group of nine patients with positive rebronchoscopy survived for a shorter time than the group with negative or inconclusive rebronchoscopies. The survival difference was only statistically significant when analyzed using the log rank test, but it was not significant when analyzed by the Wilcoxon test. The economic analysis showed that it costs $11,333 per patient reclassified when scans were redone in these patients. The cost could even have been higher had we used present-day scanning techniques (computed tomography and magnetic resonance imaging), although they might be slightly more sensitive. The cost of rebronchoscopy per patient reclassified was $14,960. Therefore, we recommend that restaging (scans or rebronchoscopy) not be done in responding patients with limited small cell lung cancer, thus potentially saving health care dollars as well as reducing patient inconvenience with no detrimental effect on survival.