To determine the value of reoperation alone (no further surgical procedures or radiotherapy), 43 patients (27 men, 16 women) with recurrent supratentorial glioblastomas who underwent a second craniotomy for recurrent tumour were reviewed retrospectively. The patients ranged in age from 27 to 66 years (median 53 years). All patients were treated initially by surgical resection and external radiation (50 Gy in 25 fractions through parallel opposed regional fields). In addition, 10 patients (23%) received chemotherapy, 3 patients (7%) received photodynamic therapy and 9 patients (21%) received interstitial brachytherapy postoperatively. Although none of the patients had further surgical procedures or radiotherapy after reoperation for tumour recurrence, 5 of the 43 did receive single-agent chemotherapy. The median survival after the first operation was 57 weeks. The median interval between first and second operations was 32 weeks. Median survival after reoperation was 19 weeks. An interval of more than 50 weeks between the two operations correlated with a significant (p < 0.05) increase in survival. The death rate for reoperation was 4.6%. The infection rate was 9.3%. The authors conclude that reoperation alone confers a modest but valuable increase in survival, especially if the interval between operations is greater than 50 weeks.