Cohort review has been used internationally to support tuberculosis (TB) control. We describe its first use in the UK by a London TB service. Improvements were noted in case management and contact tracing, weaknesses identified and important service changes put in place. Key areas of impact were directly observed therapy (DOT) provision (a greater proportion of cases offered DOT, and in response to low uptake resources diverted to create posts responsible for patient-centred DOT delivery), and contact tracing (more contacts per case screened and assessed). Cohort review enables whole system review and improvement. It has subsequently been adopted across the UK.