INTRODUCTION: Primary tuberculosis (TB) of a rib is a very uncommon presentation and accounts for <
1% of musculoskeletal TB. CASE REPORT: This case report studies a 34-year-old immunocompetent individual who presented with dull-aching right-side lower chest wall pain and swelling with constitutional symptoms. A routine X-ray of the chest was performed, which revealed no abnormality. Therefore, magnetic resonance imaging was performed given soft-tissue swelling, which suggested an extra-pulmonary swelling with lytic 9th rib lesion TB. The diagnosis was confirmed using a gene-expert of ultrasound-guided aspirated material. A drug susceptibility test was done, and it was found to be rifampicin sensitive. Hence, the patient was started on anti-tubercular therapy. The patient responded to it remarkably and was symptom-free at the end of 1 year. CONCLUSION: The case illustrates that a high degree of suspicion, early diagnosis, and timely intervention are the key to management.