13021 Background: Current standard treatment of newly diagnosed GBM is radiotherapy (RT) with concurrent Temozolomide (TMZ), followed by TMZ according to the EORTC/NCIC trial. MGMT promoter methylation status has been correlated with prolonged overall survival (OS) and survival benefit from treatment with TMZ and RT. The aim of our study is to assess the efficacy of this schedule in a cohort of patients (pts) out of a trial, and the prognostic implication of the MGMT methylation status in the same unselected population. Methods: From March 2002 to December 2005 89 pts were reviewed from 8 centers. A Kaplan Meier method and a multivariate analysis (MA) using the Cox model were performed to study the time to progression (TTP) and OS. DNA was available from paraffin in 71 samples. DNA was modified with bisulfit, and methylation specific PCR (MSP) was performed. MGMT promoter methylation status was assessed in 62 (69%) pts. Results: Median age 57 years(y) (18–80). 61,8% males. Complete resection (CR) in 33,7%, partial resection (PR) 48,3% and biopsy (B) 18%. Median Karfnosky (IK)90% (40–100). 58% needed dexamethasone (DXM) during RT. 92,1% completed RT-TMZ. 80,9% started adjuvant TMZ. 40,4% completed 6 cycles. Median number of cycles: 4. Median follow up 23 months(m). TTP: 6,9m (CI: 5,4–8,5). In the MA extend of surgery (RR CR vs PR: 1,43 (CI:0,83–2,43) and RR CR vs B: 2,22 (CI: 1,14–4,3)) and age >60y(RR 1.88 CI:1.17–3.04) were significant for recurrence. Median OS: 13,6m (CI 12.1–15.2). DXM treatment RR=1.96 (IC: 1.1–3.4) and >60y RR=1.94 (IC: 1.15–3.28) were significant in the MA for survival. No statistical difference was seen for gender, IK. MGMT methylation: 45,2%. Median survival for patients with methylated MGMT: not reached. Median survival for unmethylated: 12,5m. (p 0,029). No statistical difference was found in TTP according to methylation of MGMT (p 0,6). Conclusions: OS and TTP of this pts were similar to the EORTC/NCIC trial. Determination of methylation of MGMT is feasible and reproducible in the clinical practice. The % of methylation that we found is similar to previously reported. Methylated MGMT is a favourable prognostic factor for OS. Age> 60y and extend of surgery are prognostic factors for PFS, while DXM and age are for OS. No significant financial relationships to disclose.