The prognostic value of interim positron emission tomography (PET) interpreted according to visual criteria is a matter of debate in diffuse large B-cell lymphoma (DLBCL). Maximal standardized uptake value reduction (ΔSUVmax) may better predict outcome. To compare the prognostic value of both methods, we analyzed PET done at baseline (PET0) and after 2 (PET2) and 4 (PET4) cycles in 85 patients with high-risk DLBCL enrolled on a prospective multicenter trial. All images were centrally reviewed and interpreted visually according to the International Harmonization Project criteria and by computing ΔSUVmax between PET0 and PET2 (ΔSUVmaxPET0-2) or PET4 (ΔSUVmaxPET0-4). Optimal cutoff to predict progression or death was 66% for ΔSUVmaxPET0-2 and 70% for ΔSUVmaxPET0-4. Outcomes did not differ significantly whether PET2 and PET4 were visually positive or negative. Inversely, ΔSUVmaxPET0-2 analysis (> 66% vs ≤ 66%) identified patients with significantly different 2-year progression-free survival (77% vs 57%; P = .0282) and overall survival (93% vs 60%; P < .0001). ΔSUVmaxPET0-4 analysis (> 70% vs ≤ 70%) seemed even more predictive for 2-year progression-free survival (83 vs 40%; P < .0001) and overall survival (94% vs 50%; P < .0001). ΔSUVmax analysis of sequential interim PET is feasible for high-risk DLBCL and better predicts outcome than visual analysis. The trial was registered at http://clinicaltrials.gov as NCT00498043.