In Slovakia, since October 2012, crizotinib has been available for the treatment of adults with previously treated ALK-positive advanced NSCLC, based on the therapeutic indication approved by the European Medicines Agency. The purpose of this study was to assess the results achieved with crizotinib in the treatment of NSCLC in clinical practice in Slovakia, and to compare them with the results from the key clinical trial PROFILE 1007. In the multicenter retrospective study, approved by the Ethical Committee of the Specialized Hospital of St Zoerardus Zobor, the data of 34 ALK-positive patients from 8 centers were reviewed. Data regarding ALK testing and results were obtained from the central laboratory database (Comenius University Jessenius Medical Faculty and Martin's Biopsy Centre). Data regarding patients were obtained from the databases of participating institutions and patient files. Fluorescence in situ hybridization (FISH) with break-apart probes was used for the confirmation of ALK rearrangement in all cases. Response to treatment was evaluated using RECIST criteria v. 1.1. Statistical analyses were performed using MedCalc® software. PFS and OS were estimated using the Kaplan–Meier method. Between October 2012 and December 2015, 34 ALK-positive patients with locally advanced or metastatic NSCLC were treated with crizotinib, 31 of them after the first-line chemotherapy. Characteristics of patients: median age, years (range): 58 (23-77), ECOG/WHO PS: 0, 1, 2, 3 in 1, 23, 6, and 4 patients, respectively. Histology: adenocarcinoma in 33 cases, NSCLC, NOS in one. Patients with locally advanced disease: 2, with metastatic disease: 32. Median PFS was 18 months (95% CI: 13 - 22), median OS (number of events: 13, 38,24%): 32 months (95% CI: 18 - 32), response rates: CR + PR: 3 + 23, 76,5% (95% CI 50-100%), SD: 7, 21,5%, PD: 3, 8,8%, not stated: 1. There was a significant improvement in PS within 2 month, mean difference: - 0,62, p = 0,0025. Grade 3/4 toxicities occurred in 15/2 patients. Crizotinib was permanently discontinued due to AEs in 2 patients only. PFS and OS in our study were numerically better in comparison with PROFILE 1007. On the other hand, common grade 3 toxicities occurred also more often. Our study provides real-world evidence of the efficacy of crizotinib in patients with ALK-positive NSCLC, treated outside of clinical trials.