As part of its Medical Technologies Evaluation Programme, the National Institute of Health and Clinical Excellence (NICE) invited the manufacturer, Covidien, to provide clinical and economic evidence for the evaluation of the Pipeline™ embolization device (PED) for the treatment of complex intracranial aneurysms. Cedar; a consortium between Cardiff and Vale University Health Board and Cardiff University, was commissioned to act as an External Assessment Centre (EAC) for NICE to independently critique the manufacturers' submissions. This article gives an overview of the evidence provided, the findings of the EAC and the final guidance published by NICE. The scope issued by NICE considered PED as the intervention in a patient population with complex unruptured intracranial aneurysms (IAs), specifically large/giant, wide-necked and fusiform aneurysms. The comparator treatments identified were stent-assisted coiling, parent vessel occlusion, neurosurgical techniques and conservative management. The manufacturer claimed that PED fulfils a currently unmet clinical need in the treatment of large or giant, wide-necked or fusiform IAs. Thirteen studies were identified by the manufacturer as being relevant to the decision problem, with two of these included for data extraction. The EAC identified 16 studies as relevant, three of which had been published after the manufacturer's search. Data extraction was carried out on these studies as, although many were low level research comprising of case reports and case series, they provided useful, pertinent safety and outcome data. No relevant economic studies of the device were identified; therefore, a new economic model was designed by the manufacturer. The base-case scenario provided recognized the costs of PED to be higher than the costs for endovascular parent vessel occlusion, neurosurgical parent vessel occlusion, neurosurgical clipping and conservative management. However, PED was found to be cost saving compared with stent-assisted coiling, with a saving of £13,110 per patient. Analysis of the clinical data suggested that treatment with PED has high rates of clinical success with high rates of aneurysm occlusion and acceptable adverse events for the patient population. Economic evidence suggested that the costs in the base-case for PED may have been underestimated, meaning that PED would only become cost saving in patients who would otherwise require treatment with 32 coils or more. NICE Medical Technologies Guidance MTG10, issued in May 2012, recommends the adoption of PED in selected patients within the UK National Health Service (NHS).