Subjects were 45 patients with angioimmunoblastic T-cell lymphoma (AITL) who underwent 2-[F-18]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography/computed tomography (PET/CT) at baseline and interim after 2-4 cycles. Predictors of progression-free survival (PFS) and overall survival (OS) were assessed. Positive interim PET/CT (Deauville score >= 3) was a significant independent predictor of poor PFS (Hazard ratio, 4.42; p=.028), and showed marginal significance to predict OS (p=.065). Less than 60% decrease in the average change of maximum standardized uptake value normalized by lean body mass (SULmax) also was a significant independent predictor of poor PFS (Hazard ratio, 12.96; p=.001) and poor OS (Hazard ratio, 24.11; p=.006). Interim PET/CT has a significant prognostic value for predicting PFS and OS in patients with AITL. Deauville score and percent decrease of SULmax have the potential to be useful parameter in classifying patients into good and poor responders.