Rationale: Lung adenocarcinoma is the most common pathologic pattern of lung cancer. During the past decades, a number of targeted agents have been explored to treat advanced lung adenocarcinoma. Recently, Crizotinib, the antagonist of anaplastic lymphoma kinase (ALK), has been widely used in ALK-rearranged lung cancer treatment. Crizotinib is generally well tolerated while its most frequent adverse events include visual disorders, gastrointestinal disturbances, cardiac and endocrine abnormalities. Rash caused by crizotinib is rarely seen, and there are few case reports of severe rash caused by crizotinib. Patient concerns and diagnoses: Here we report cases of an 81-year-old man and a 66-year-old woman with ALK-rearranged advanced lung adenocarcinoma. When patients came to our department, they both had crizotinib-induced severe rash. Interventions: Crizotinib was initiated as the 1st-line treatment without other therapies. We treated severe rash with traditional Chinese medicine (TCM) therapy called Zhiyang Pingfu liquid along with Western medicine. Zhiyang Pingfu liquid consists of Scutellaria baicalensis 20g, Portulaca oleracea 30g, Cortex Dictamni 30g, Sophora flavescens 30g, and other substances. Western medicine includes Minocycline hydrochloride tablets and Aprepitant capsules. Outcomes: Both patients achieved a partial response when treated with crizotinib, and suffered from severe rash. With Zhiyang Pingfu liquid and Western medicine, their rash gradually disappeared with no sign of cancer progression. Also the male patient did not relieve after taking only antibiotics (standard therapy) and anti-allergic medicine. Lessons: Despite the dramatic benefit of crizotinib for patients with ALK rearrangement, crizotinib-induced severe rash needs to be dealt with caution. This is the 1st case in which TCM and Western medicine are used to successfully treat crizotinib-induced severe rash. The mechanism of crizotinib-induced rash deserves further attention in future research.