Objective: The Supporting the Improvement and Management of Prescribing for Urinary Tract Infections (SIMPle) study, a cluster randomized trial, sought to improve the quality of antibiotic prescribing for Urinary Tract Infections in General Practices located in the west of Ireland. This paper presents the process evaluation and intends to provide insights into the antibiotic prescribing behaviour of the General Practitioners (GPs) during the intervention. The paper discusses how the social marketing intervention developed as part of SIMPle resulted in GPs prescribing more first line antibiotics, the aim of the trial. However it also offers insights into why antibiotic prescriptions increased during the intervention period. Methods: Fifteen GP interviews and summative intervention components including monitoring practice participation and information provided to the study team. Thematic analysis was used to analyze transcripts. Results: GPs recognized the value of consultation coding to produce practice specific audit and feedback reports including current antibiotic prescribing and providing evidence which motivated change. Conclusions: The SIMPle study was successfully integrated into routine care. By simplifying GPs' access to up to date evidence on their prescribing behaviors, GPs can be positively influenced beyond the context of an intervention.