Gefitinib has shown good efficacy in patients with EGFR mutation-positive non-small-cell lung cancer, but acquired resistance is inevitable. Here we report a patient with an advanced lung adenocarcinoma with the EGFR mutation who achieved surgical opportunity and long-term survival following treatment with chemotherapy and bevacizumab, followed by sequential gefitinib combined with allogeneic haploidentical CD8 + CD56 + natural killer T cells. Our case provides a potential effective strategy for delaying acquired gefitinib resistance and extending progression-free survival among patients with non-small-cell lung cancer who harbor common EGFR mutations.