We have investigated prognostic factors for survival in a series of 26 patients with chordoma treated in Lyon, France, between 1979 and 1993. In this series, the median progression-free (PFS) and overall survival (OS) were 10 and 90 months, respectively. In univariate analysis, PFS, but not OS, was found significantly longer in males as compared to females (median: 19 versus 7 months, P = 0.05); and patients under 60 years of age had a longer PFS (median: 18 versus 6 months; P = 0.06) and OS (median: 108 versus 47+, P = 0.05) than older patients. A favourable prognostic subgroup including male patients under 60 years and a poor prognostic group including female patients and male over 60 years were thus defined (median PFS: 36 versus 6 months, P = 0.001; median OS: 108 versus 55+, P = 0.15). Primary treatment combining surgery and postoperative radiotherapy was associated with a longer PFS than surgery only (median: 36 versus 7 months, P = 0.002) in the whole series and in both prognostic subgroups.