['Glucose metabolic activity measured by [(18)F]-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) has shown prognostic value in multiple malignancies, but results are often confounded by the inclusion of patients with various disease stages and undergoing various therapies. This study was designed to evaluate the prognostic value of tumor FDG uptake quantified by maximum standardized uptake value (SUVmax) in a large group of early-stage non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiotherapy (SBRT) using consistent treatment techniques.', 'Two hundred nineteen lesions in 211 patients treated with definitive SBRT for stage I NSCLC were analyzed after a median follow-up of 25.2 months. Cox regression was used to determine associations between SUVmax and overall survival (OS), disease-specific survival (DSS), and freedom from local recurrence (FFLR) or distant metastasis (FFDM).', 'SUVmax >3.0 was associated with worse OS (p<0.001), FFLR (p=0.003) and FFDM (p=0.003). On multivariate analysis, OS was associated with SUVmax (HR 1.89, p=0.03), gross tumor volume (GTV) (HR 1.94, p=0.005) and Karnofsky performance status (KPS) (HR 0.51, p=0.008). DSS was associated only with SUVmax (HR 2.58, p=0.04). Both LR (HR 11.47, p=0.02) and DM (HR 3.75, p=0.006) were also associated with higher SUVmax.'] Is fDG-PET maximum standardized uptake value prognostic for recurrence and survival after stereotactic body radiotherapy for non-small cell lung cancer?