Clients on Opioid Substitution Therapy (OST) may be at risk of TB. We screened for tuberculosis in asymptomatic OST clients using Chest-X-ray (CXR) and sputum from those with CXR suggestive of TB were tested using Xpert MTB/Rif. Among 472 who underwent CXR, 0.1% had CXR suggestive of TB. The number needed to screen was 118 clients for one CXR suggestive of TB. All four clients with CXR suggestive of TB underwent MTB/Rif assay and one was diagnosed with TB. The TB patient was asymptomatic and could have been missed through the passive approach. We recommend further studies to explore ACF among OST clients.