Inappropriate prescribing of antibiotics is a contributing factor to Antimicrobial Resistance, especially when managing Upper Respiratory Tract Infections. In the United Kingdom, nurses can independently prescribe, yet little is known about their antibiotic prescribing behaviour. This PhD aimed to explore Nurse Independent Prescribers’ antibiotic prescribing behaviour and the influences on this behaviour. An analysis of nationally gathered prescribing data was carried out to describe current nurse antibiotic prescribing practice in Scotland. The Reasoned Action Approach, a behavioural theory, was chosen as the theoretical framework for this four-phased mixed method study. Telephone interviews took place with 27 Nurse Independent Prescribers from Scotland. Content analysis revealed the most frequently occurring beliefs which were subsequently used in the development of a questionnaire. This was piloted and then used in an online survey, sent to all Nurse Independent Prescribers in Scotland. Descriptive and inferential statistical analysis was carried out using SPSS© to establish the key determinants of their behaviour (n=184). Findings from Phase One show that nurse prescribing of antibiotics is increasing in Scotland and suggest that Nurse Independent Prescribers are adhering to prescribing quality indicators. Findings from Phase Four demonstrate that Nurse Independent Prescribers intend to manage patients who present with an Upper Respiratory Tract Infection without prescribing an antibiotic. Key significant influences which determined their intention to manage these patients without prescribing an antibiotic were; social influence from other nonmedical prescribers, pressure from patients/carers to prescribe an antibiotic (barrier) and experience and confidence (facilitator). An intervention to maximise appropriate prescribing should therefore focus on reducing the influence of patient pressure on making Nurse Independent Prescribers less likely to manage patients without prescribing an antibiotic. Interventions which use the positive influence from other nonmedical prescribers, or try to change Nurse Independent Prescribers’ beliefs about their capability to manage these patients, should also prove effective. These positive results should be shared with commissioners of healthcare service as well as with the Nurse Independent Prescriber population and future nurse prescribers as a positive reinforcement of their appropriate prescribing behaviour, especially due to the influence that other nonmedical prescribers have on their behaviour.