Aim To review the provision of out-of-hours interventional radiology (IR) services in the London Strategic Health Authority (SHA). Materials and methods All 29 acute hospitals in the London SHA were contacted between November 2008 and January 2009. A questionnaire based on the Royal College of Radiologists (RCR) guidelines assessed the provision of out-of-hours IR services. An “ad-hoc” service was defined as on-call provision where not all the radiologists could perform intervention: If IR was required out of hours, an interventionalist came in when off-duty or the patient was transferred. Results Seventeen out of the 29 (59%) hospitals provided ad-hoc out-of-hours services, eight (28%) provided a 24-hour rota, and four (14%) provide no out-of-hours cover. No ad-hoc service had formal transfer arrangements to a centre providing a 24 h service. Only two hospitals providing a 24 h service had six radiologists on the rota. Conclusion Strategic planning for out-of-hours IR across London is recommended. This is likely to be welcomed by the hospitals involved, allowing informal arrangements to be formalized, and collaboration to provide comprehensive regional networks, provided appropriate funding is made available. A national audit is recommended; it is unlikely these findings are unique to London.