Resistance to ROS1 tyrosine kinase inhibitors is inevitable, but it has been unclear whether crizotinib might be effective after the development of entrectinib resistance. We here present a case ofROS1-rearranged NSCLC that responded to crizotinib after tumor progression due toMETpolysomy during entrectinib treatment. This case suggests that crizotinib is an effective option for patients withMETpolysomy, even after disease progression on entrectinib.