The aim was to examine current scope of practice among nurses and midwives in Ireland. The objectives were to describe practitioners' self-reported facilitators and barriers to expanding scope of practice and to develop a scope of practice barriers scale. Regulatory authorities permit practice expansion, so long as it falls within accepted parameters of scope of practice. Enduring difficulties in relation to scope of practice include the difficulty of balancing practice restriction with practice expansion. A postal survey design was used to examine registered nurses' and midwives' current scope of practice, including their experiences of facilitators and barriers to expanding practice. A stratified random sample of registered nurses and midwives in Ireland was surveyed using the Scope-QB, a 19-item self-report scope of practice barriers scale. Based on a sample of 1010 respondents, the self-reported perceived barriers to practice expansion included fear of legal consequences, time restrictions and lack of remuneration. Professional satisfaction, patients' needs, organisational support and having access to continuing professional education were perceived as facilitators of practice expansion. Older nurses and midwives as well as nurses and midwives holding more senior promotional grades, such as clinical nurse manager grades, perceived fewer barriers than their younger and more junior counterparts. Nurses and midwives continue to experience difficulties in relation to expanding their practice. Practitioners can operate to optimal scope of practice when practitioner-centred and workplace-based circumstances are optimal. The optimal circumstances for practice expansion exist when the facilitators of practice expansion outweigh the barriers. Given the critical role that nurses and midwives play in modern health services, it is important that they are empowered and enabled to expand their practice and to work to full scope of practice when patient needs and service requirements warrant it.