We report on a 90-year-old male patient with a ROS1-translocated adenocarcinoma of the lung who was treated with crizotinib as first-line therapy. After 11 months of treatment, we noticed complete metabolic response as measured by (18)F-FDG-PET/CT scan and a partial response according to RECIST criteria. This patient indicates that ROS1 translocations are not restricted to young age, female gender and low stage. Furthermore, this case illustrates exemplarily that crizotinib therapy is effective and manageable even as first-line treatment in elderly patients with comorbidities. Based on our findings, we recommend to include elderly patients with advanced pulmonary adenocarcinomas in molecular screening approaches for ROS1 translocations.