Introduction: Nonprescription sildenafil was introduced to the United Kingdom in 2018 as the first pharmacy service concerning sexual function, an important but often ignored factor for quality of life. Aim: This study aimed to evaluate pharmacists' views on providing nonprescription sildenafil, their perceptions of the barriers and facilitators to provide this service and strategies to overcome potential barriers, using a theorybased approach. Methods: Community pharmacists were purposefully sampled in Northern Ireland, followed by snowball sampling. Face-to-face interviews were conducted between October 2019 and January 2020. The semi-structured interviews used a piloted topic guide based on the 14-domain Theoretical Domains Framework (TDF). All interviews were audio-recorded, transcribed verbatim and anonymized. Transcripts were analyzed deductively in NVivo 13, utilizing the TDF domains as coding categories. Within each domain, content analysis was utilized to identify barriers and facilitators. Main Outcome Measure: Barriers and facilitators within the TDF domains for pharmacists to provide nonprescription sildenafil. Results: Ten pharmacists were interviewed to reach data saturation. Eight pharmacists had experience with dispensing nonprescription sildenafil. They valued nonprescription sildenafil as an additional service ("Social/professional role and identity"). Training, concise product guidelines, and private consultation areas were important facilitators ("Environmental context and resources"). The service required trusting clients ("Optimism"), with concerns about abuse and men not visiting their GP. From experience gained, pharmacists became more confident dealing with difficult situations such as patients being vague about their medical history or alcoholism or mental problems as causes for erectile disfunction (ED) ("Skills" and "Beliefs about capabilities"). Pharmacists considered lifestyle and medication causes of ED important but preferred to focus on safe supply. In general, pharmacists were satisfied with the perceived professional recognition, using their clinical knowledge or helping patients resume sexual relationships ("Beliefs about consequences"). Conclusion: Pharmacists welcomed nonprescription sildenafil to enhance their role as easily accessible healthcare providers for patients.