Although tuberculosis (TB) is considered to be a common disease confined to undeveloped or developing countries, it may also appear in countries that accept great migrant influx from endemic areas. In terms of the skeletal system, it can be involved in 1-6% of tuberculosis patients while the knee joint is the third most frequently affected site after spine and hip. Given that systemic symptoms are present in only one-third of patients with skeletal tuberculosis and secondary septic arthritis, TB is often indolent and diagnosis can hence be missed or delayed. As a result, a high index of suspicion is imperative. Here, we aim to report a case of mono-arthritis caused by Mycobacterium tuberculosis in a native 77-year-old man who was suffering from low-grade knee pain for six months and despite multiple presentations to the Accident and Emergency department, diagnosis had not been established.