Aim of the work: is to investigate the diagnostic accuracy of surveillance FDG PET/CT scans in early relapse detection in non-Hodgkin's lymphoma patients coming in complete remission after their primary line of therapy. Material and Methods: This prospective study was conducted on 72 patients with NHL (37 males and 35 females) with median age of 52 years. All patients who achieved the first complete remission were scheduled for PET/CT scans every 6 months for the first 2 years. Deauville criteria, SUV max and TLG of all lesions during end of primary line of treatment (if present) and at the time of relapse were measured. Results: 56.9% of patients were classified as stage IV. During follow up 30 patients were in complete remission (41.7%), whereas 37 patients had relapse (51.4%), and 5 patients had indeterminate relapse (6.9%). In our study 26 patients of the relapsed group (70.3%) complained of clinical symptoms suspicious for relapsing disease, while only 11 patients (29.7%) did not show clinical manifestations suspicious for relapse before undergoing the follow up PET/CT scan with significant difference (P˂0.001). 21 patients of the relapsed group (56.8%) were proved positive by follow up PET/CT as progressive disease, 9 patients (24.3%) was proved by biopsy. 3 patients (8.1%) have undergone conventional imaging CT or MRI with suspicious disease before referral for PET/CT. Only four patients (10.8%) showed regressive course after second line of chemotherapy within close follow up PET/CT. Deauville score at the time of relapse showed 11 patients were presenting with Deauville 4 (29.7%) and the remaining 26 patients showed Deauville 5 score (70.3%). Diagnostic accuracy of using surveillance PET/CT for early relapse detection in reference to other diagnostic methods showed sensitivity 97.3%, specificity 85.7%, positive predictive value 87.8%, negative predictive value 96.7% and accuracy 91.6%. Conclusion: Routine surveillance imaging with PET/CT with NHL in CR is valuable in detection of early relapse in symptomatic patients. Metabolic PET/CT parameters including SUV max and TLG are available additive parameters during follow up.