Background: The results of current studies are considered acceptable evidence to support the hypothesis of efficacy of the proposed combination of immunotherapy with chemotherapy (CT-IO) in patients with NSCLC stages Ib-IIIA candidates for adjuvant treatment. Methods: This is an open-label, randomised, two-arm, phase III, multi-centre clinical trial. Primary objective and endpoint: The primary objective is disease free survival (DFS) defined time from randomization to the earliest event defined as disease recurrence, any new lung cancer (even in the opposite lung), or death from any cause at any known point in time Sample size: 210 patients NSCLC stages Ib-IIIA (Experimental Arm (Adjuvant Chemotherapy-Inmunotherapy + maintenance adjuvant Inmunotherapy): 105 patients, Control Arm (Adjuvant Chemotherapy): 105 patients Treatment Patients randomised to the experimental arm will receive Nivolumab 360mg + Paclitaxel 200mg/m2 + Carboplatin AUC5 for 4 cycles every 21 days (+/- 3 days) as adjuvant treatment followed by maintenance adjuvant treatment for 6 cycles with Nivolumab 480 mg Q4W (+/- 3 days). Patients randomized to the control arm will receive Paclitaxel 200mg/m2 + Carboplatin AUC5 for 4 cycles every 21 days (+/- 3 days) followed by 2 observation visits. Total trial duration: 6.5 years, 3.5 years of recruitment, 1 year of adjuvant treatment or observation and 2 years of follow up. The start date was January 2021. The estimated primary completion date is June 2027. Clinical trial information: NCT04564157