A 48-year-old female patient with late stage lung cancer was admitted at Baoding Second Central Hospital on October 16, 2020. The patient reported numbness in both hands, persistent back pain, abdominal pain and diarrhea, long-term constipation, anemia, and progressive weight loss. Physical examination after admission showed no palpable enlargement of superficial lymph nodes, and clear breath sounds in both lungs, and positive percussion pain on 7-8 thoracic vertebrae in the back. Laboratory tests, hemoglobin 88 g/L. A large number of active parasites were found under the low magnification by microscope on the routine smear, and the eggs were found under the high magnification by microscope. Combined with the patient’s medical history, clinical manifestations and related auxiliary examinations, the diagnosis of Ehrlichen worm disease was made. The patient received oral albendazole (400 mg each time, twice a day) for 5 days. The patient was reviewed for the routine smear microscope on October 21 and November 16, respectively. No parasites were found under the routine smear microscope, the symptoms improved, the anemia improved, and the weight increased significantly.