INTRODUCTION: The anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI) alectinib was approved in Japan in 2014 for the treatment of ALK fusion gene-positive advanced non-small cell lung cancer (NSCLC). With the approvals of crizotinib in 2012 and ceritinib in 2017, Japan became the first country with multiple ALK TKIs available for first-line or later use in patients with ALK-positive advanced NSCLC. Here, we collected and evaluated real-world data on ALK TKI clinical usage patterns and sequencing in patients with ALK-positive NSCLC in Japan. METHODS: This retrospective observational study used the Japanese Medical Data Vision database to analyze data from patients with a confirmed diagnosis of lung cancer who visited a healthcare facility in the database between April 2010 and March 2017, underwent an ALK test, received a prescription for an ALK TKI, and were at least 18 years old as of the date of the first ALK TKI prescription. There were no exclusion criteria. Descriptive analyses of demographics, baseline characteristics, ALK TKI treatment patterns and sequences, non-ALK TKI treatments received before, during, and after ALK TKI treatment, and treatment durations were reported. RESULTS: A total of 378 patients met the inclusion criteria and were evaluated in mutually exclusive groups of patients receiving one, two, or three ALK TKIs. The initial ALK TKI prescribed was crizotinib for 52.1% of patients and alectinib for 47.9% of patients; however, the proportion of patients receiving alectinib as the initial ALK TKI increased over time following the Japanese approval of alectinib in 2014. Of the 117 patients who received two or three ALK TKIs, 106 received crizotinib as the first ALK TKI and 11 received alectinib. Before the date of the patient's first ALK TKI prescription, 153 of 378 patients (40.5%) had received chemotherapy. Of 104 patients who discontinued ALK therapy, 46.2% received chemotherapy and 5.8% received immunotherapy as their next treatment. CONCLUSION: At the time of this analysis, most patients who received more than one ALK TKI received crizotinib as the initial ALK TKI. Additional ALK TKIs have since been approved in Japan as first-line or later therapeutic options for patients with ALK-positive NSCLC, but the optimal sequence of ALK TKI usage remains undetermined. As new data continue to emerge, additional research will be warranted to evaluate ALK TKI sequences that do not include crizotinib as the first therapy in this patient population.