Pyogenic spondylitis is regarded as a rare infectious disease. The incidence of this disease has been increasing recently due to an increase in the ratio of elderly people in the population as well as an increase in immunocompromised hosts complicated by cancer, diabetes mellitus and liver cirrhosis. Allogeneic hematopoietic stem cell transplantation (HSCT) is now performed widely as a curative treatment for various malignant hematological diseases. However, allogeneic HSCT causes chronic immunocompromise. There is no case report describing infectious spondylitis after HSCT. Here we describe a case of infectious spondylitis after HSCT and discuss risk factors and treatment. The patient was a 56-year-old female with AML-M1 who underwent allogeneic HSCT in our hospital. She developed back pain and fever about 150 days after HSCT and became unable to walk due to the severity of back pain. MRI T1 images showed a low intensity area, T2 images showed a high intensity area and Gd-DTPA-enhanced images showed a high intensity area at the S1-2 disk space. Clinical findings and MRI findings suggested pyogenic spondylitis. Back pain improved gradually after conservative treatment with meropenem (MEPM) for two weeks. After 4 weeks of MEPM administration, she had fully recovered and there has not been any recurrence of back pain to date. In conclusion, pyogenic spondylitis should be considered in the differential diagnoses for HSCT recipients with severe back pain.