Abstract: This study discusses a case of brucellosis infection complicated by thrombocytopenia and spondylitis in an elderly individual from a non-pastoral area to enhance clinicians' understanding of this condition. Blood samples were collected for laboratory examination, and literature was reviewed. Evidence-based medicine and clinical reasoning were employed to unravel the etiology. The patient's fever and back pain were attributed to brucellosis infection. Laboratory tests, including the Rose Bengal Plate Agglutination Test, Tube Agglutination Test and lumbar magnetic resonance imaging, were consistent with brucellosis complicated by spondylitis. Despite treatment, the patient's platelet count did not significantly increase, raising concerns about hematological disorders. Further bone marrow aspiration and hematological examinations were conducted to ascertain the cause of thrombocytopenia. Hormonal therapy yielded significant results, and the patient was fully recovered after continuous follow-ups. The brucellosis combined with secondary immune thrombocytopenia and spondylitis of the patient is relatively rare in clinical practice, and clinicians may easily miss the diagnosis of immune thrombocytopenia based on experience.