Abstract In New Zealand approximately 4600 people receive opioid substitution treatment (OST) for opioid dependence, primarily methadone maintenance treatment. This study explored ways in which OST could be improved, given the significant waiting times for treatment. Two parallel surveys were conducted: 1) peer interviews with 85 regular daily or almost daily opioid drug users (51.8% receiving OST, 18.8% not currently receiving OST, and 29.4% never received OST) and; 2) a census of all 18 specialist OST service providers. When asked how OST might be improved, the four categories most commonly cited by the opioid users were ‘better treatment by staff’, ‘more flexibility’, ‘better takeaway arrangements’, and ‘decreased waiting time’. Both opioid users and specialist services rated ‘restricted takeaways’ and ‘having to go on a waiting list’ in the top three perceived barriers to OST. Almost all services reported significant resource issues and barriers to the transfer of stable clients from specialist services to continuing treatment in primary care. The findings from this study indicate how OST can be made more accessible and attractive and thus achieve better uptake and retention.