This single arm study will assess the feasibility of use, safety and tolerability of Avastin(bevacizumab) in combination with chemoradiation therapy in patients with locally advanced unresectable non-squamous non-small cell lung cancer.An initial cohort of patients will receive Avastin 7.5mg/kg iv every 3 weeks, in combination with concurrent thoracic radiation for 6.6 weeks and chemotherapy (cisplatin 75 mg/m2 iv and vinorelbine 15mg/m2 iv administered according to a standard treatment protocol). If no dose-limiting toxicities are observed, a second cohort of patients will receive Avastin at a dose of 15mg/kg iv every 3 weeks, in combination with a similar treatment regimen to that of the first cohort. After 5 cycles of combination treatment, Avastin monotherapy will be administered for a further 4 cycles. The anticipated time on study treatment is 3-12 months, and the target sample size is <100 individuals.