Objective: To investigate patterns of membership and barriers to service use in the Christchurch Diabetes Society.

Methods: A socio-economic profile of the Christchurch Diabetes Society's membership was constructed by examining the residential locations of society members in Christchurch City. Rates of membership by deprivation decile were calculated by comparing the membership data to the population of people diagnosed with diabetes.

Results: Persons living in deprived areas, in particular Maori and Pacific people, are under-represented in society membership. However, there is evidence that the relationship between ethnicity and membership rates is stronger in more deprived areas.

Conclusions: This study provides further insights in understanding barriers to care and the role of NGOs. Given that groups in the community most likely to be affected by diabetes are least likely to be members of the society and to have access to the society's services, the results raise questions about the most appropriate role for local diabetes societies within a decentralised health system.