A 61-year-old female patient with non-small cell lung cancer (NSCLC) was treated with dabrafenib (150 mg twice day) combined with trametinib (2 mg once day). Two months after initiation of therapy, the patient developed fever, lower limb edema, and venous thrombosis. Dabrafenib and trametinib are approved for the first-line treatment of advanced non-small cell lung cancer with BRAF V600E-mutation, the common adverse reactions include fever, fatigue, nausea and vomiting, while venous thrombosis has been rarely reported. This article presents a case of fever, lower limb edema, and venous thrombosis associated with the combination of dabrafenib and trametinib, aiming to alert clinicians and pharmacists to the potential occurrence of such adverse events, including fever, peripheral edema, and venous thromboembolism during treatment. It may serve as a reference for adverse reaction prevention and management to improve medication safety.