Inequalities in access to appropriate and acceptable healthcare contributes to a pattern of poorer health status, reduced life expectancy and greater dissatisfaction with healthcare amongst people from Black and minority ethnic communities (BME). Language acts as a further barrier to access. The development of bilingual advocacy fuses two key functions--interpretation and advocacy--to ensure that people from BME communities are able to have their healthcare needs met appropriately. This paper explores the development of bilingual advocacy in East London, which has a highly diverse population speaking over 100 different languages. It considers the development of the bilingual advocacy services by an NHS University Hospital Trust, the local experience of these services and the factors that have influenced their development. We employed the Delphi method amongst the four authors to examine the advocate-, service- or client-related challenges that face advocacy services; and the threats of these challenges to Trust-based advocacy and their implications to the service, client and advocate. Advocate-related challenges included status, esteem and remuneration of bilingual advocates in relation to other health professionals, as well as skills development, career progression, gender, capacity building and potential research contributions. Service-related challenges included work load, case mix, administration, commissioning processes/arrangements; entrepreneurial aspects of advocacy services; and mechanisms/potentials for cost recovery. Client-related challenges included continuity of advocacy; language requirements and advocacy needs of clients; and ways in which mobile populations influence planning and delivery of advocacy services for inner city hospitals. The paper concludes with identifying the implications for future development of bilingual advocacy services and the implications for their workforce.