There are two worlds when it comes to the diagnosis of tuberculosis (TB). One world has only smear microscopy at its disposal. There may also be some radiological facilities, usually at the patients' expense. The other world has all modern techniques available, including culture, nucleic acid amplification, molecular diagnostics and sophisticated radiological techniques such as computed tomography and positron emission tomography scanning. The ability to diagnose or misdiagnose TB will vary across these two worlds. In this review, we provide an overview of clinical, radiological, molecular and immunological diagnosis of TB and highlight the common difficulties and pitfalls in TB diagnosis.