Since 1994 there have been considerable additions to the range of health care professionals (HCPs) that can prescribe in the United Kingdom (UK). These HCPs include nurses, pharmacists, radiographers, physiotherapists, podiatrists, chiropodists and optometrists. After a period of specific prescribing training these HCPs are often referred to as non-medical prescribers (NMPs). There has been a limited amount of research that has investigated the influences on the prescribing behaviour of NMPs. Additional research with NMPs would be beneficial to contribute to the currently limited understanding of the prescribing behaviour of NMPs. Knowledge about the influences on NMPs' decisions will also provide further insight into the training and support requirements of these HCPs. A programme of research was conducted to explore the influences on the prescribing behaviour of nurse and pharmacist independent and/or supplementary prescribers working in primary and community care. The research utilised a range of qualitative data collection techniques including interviews, semi-structured interviews, focus groups and the critical incident technique. The Q-method was also used. This allowed perspectives amongst NMPs about prescribing influences to be identified. In total, 104 NMPs took part in this research. This included 31 pharmacist prescribers and 73 nurse prescribers. NMPs were mainly recruited via their primary care trust prescribing lead but pharmacist prescribers were also contacted using the details they provided to their professional body. NMPs in this research occupied a wide range of roles and had diverse demographic characteristics. Relevant ethical approval was obtained before conducting this research. NMPs were motivated by their desire to feel safe, keep it simple and fit in with prescribing culture when prescribing. They also had a code of practice which underlined their rejection of some influences, such as patient pressure and logistical influences, and their acceptance of others, such as guidelines and formularies. The research found that the influences on NMPs' prescribing decisions can be best understood through identifying how and in what circumstances NMPs take responsibility for issuing prescriptions and making prescribing decisions. As well as providing insights into the training and support requirements of NMPs the findings of this research are important to others that may want to research the prescribing influences on NMPs in the future.