PURPOSE: There exists a dearth of research concerning non-small cell lung cancer (NSCLC) patients experiencing overall progressive disease concomitant with shrinking lesions after immunotherapy. This is a special type of mixed response. We aim to evaluate the clinical characteristics and treatment options of these patients during immunotherapy. PATIENTS AND METHODS: We categorized patients into two groups: Progressive Disease with Mixed Responses (PDMR) (n = 31) and Progressive Disease with None Mixed Responses (PDNMR) (n = 144), depending on whether at least one target lesion had shrunk by ≥30% at the point of overall progression. Computed tomography scans and magnetic resonance imaging were utilized to evaluate the clinicopathological significance of these patients, and a multivariate analysis was conducted to scrutinize the clinical characteristics and prognosis-influencing factors in these patients. RESULTS: Patients in the PDMR group had worse staging and a greater proportion of previous radiotherapy. The median overall survival (mOS 22 vs 36.4 months; 0.019) and median progression-free survival (mPFS 5.83 vs 9.03 months; 0.031) of the PDMR group were shorter than PDNMR group. Longer subsequent OS with continued immunotherapy after PDMR compared with patients who do not continue with immunization after PDMR (mOS 23.9 vs 6.5 months; = 0.024). CONCLUSION: PDMR was primarily observed in stage IV patients and previously irradiated patients. OS and PFS were inferior in patients with PDMR compared to patients with PDNMR. The continuation of immunotherapy in PDMR patients could extend their survival.