At present, there is no universally accepted cancer pain assessment tool for use in palliative care (PC). The European Palliative Care Research Collaborative (EPCRC), therefore, aims to develop an international consensus-based computerised pain assessment tool. As part of this process, we have performed (1) a literature review on pain assessment tools for use in the PC and (2) an international expert survey to gain information on the relevant dimensions for pain assessment in PC. 230 publications were identified, only six met the inclusion criteria. Three further articles were identified through manual searching, totalling 11 different pain assessment tools. Nine tools were multidimensional. Pain intensity was assessed in seven, using various numerical/verbal rating scales (NRS/VRS); five tools focused on pain management. Three publications did not identify the rationale for the need to develop a new tool, and the selection procedure for items/dimensions was not described in six tools. Patient and/or professional expert groups were involved in the development of five tools and only two tools were extensively validated or cross-culturally tested. Thirty-two experts (71%) completed the expert survey and identified 'intensity', 'temporal pattern', 'relief/exacerbation', 'pain quality' and 'location' as the five most relevant dimensions. Most preferred assessment of 'pain intensity' was by NRS rather than VRS. Time windows extending 24 h were regarded as less relevant. Development of PC pain assessment tools seems to be a continuous process, which does not adhere to systematic guidelines, thus does not contribute to a universally accepted tool. No tool contained all relevant dimensions as defined by the experts. Many tools focused on particular dimensions, suggesting that specific research interests may drive the tool development process. Extensive literature reviews, expert and patient input and clinical studies are a needed approach in the development of a new consensus-based pain assessment tool.