Childhood tuberculosis (TB) has long been neglected by TB control programmes, as children tend to develop sputum smear-negative disease and rarely contribute to disease transmission. However, children suffer severe TB-related morbidity and mortality in areas with endemic TB and carry a significant proportion of the global disease burden. Apart from improved control of the global TB epidemic, access to accurate diagnosis and effective treatment is essential to reduce the disease burden associated with childhood TB. Access to child friendly anti-TB treatment is improving, but establishing an accurate diagnosis remains a challenge. This review provides an overview of recent advances in the diagnosis of childhood TB, focusing on bacteriological, immunological, radiological and symptom-based approaches. It is possible to establish a fairly accurate diagnosis of either latent infection or active TB in immunocompetent children, even in resource-limited settings, but establishing an accurate diagnosis of TB in HIV-infected (immunocompromised) children remains a major challenge.