INTRODUCTION: Research highlights discrepancies in recognition of borderline personality disorder (BPD) in men, despite similar rates of prevalence across genders. To investigate inpatient mental health professionals' experiences of delivering treatment for males with a diagnosis of BPD. Six mental health professionals working within adult acute inpatient wards completed a semi-structured interview. All participants were members of the nursing team. Thematic analysis was used to analyse the data. Five themes were identified: Gender Differences, Stereotyping, Facilitators to Care Delivery, Barriers to Care Delivery and Ways to Improve Care. Participants talked of a lack of awareness and understanding of BPD in males impacting both diagnosis and treatment in an acute inpatient setting. There may be factors ranging from gender stereotypes, limited knowledge and understanding of gender differences in presentations, and personal/organisational cultures influencing the formulation and treatment of males with a diagnosis of BPD in inpatient settings. The findings suggest that gender stereotypes such as masculine norms may influence how male patients' emotional difficulties are understood and managed, and that additional training in male-specific issues to improve knowledge and care provision. This research will support inpatient staff, service leads and clinical educators to identify ways to adapt care provision for men.