Background: Professional nurses play a significant role in the professional socialisation of learner nurses during clinical placement. Clinical placements are areas of experiential learning as learner nurses come in contact with real-life experiences. Professional nurses are custodians of learners and need to offer them support.Aim: The study sought to explore the role of professional nurses in supporting learner nurses during professional socialisation.Setting: Four clinical health facilities in Limpopo province at different levels of care were purposely sampled to obtain information from different levels of care.Methods: An ethnonursing approach and qualitative, explorative design was used. Non-probability purposive sampling was used to select 25 professional nurses. The criteria were professional nurses with 3 years of experience in professional socialisation and working in institutions accredited for clinical placement of learner nurses registered in the undergraduate programme. Data were collected through a face-to-face interview until data saturation was reached. Tesch’s open coding system was used to analyse data.Results: Professional nurses acknowledged that their responsibilities in supporting learners during professional socialisation are mentoring, teaching and being competent practitioners. Professional nurses were aware of their role in transferring ethical skills and knowledge to learners through professional socialisation.Conclusion: The effectiveness of professional socialisation of learner nurses depends on the support offered during clinical placements.Contribution: The study adds to the body of knowledge in nursing education and practice because when learners are offered support in the clinical areas, their learning journey will be of positive experience leading to competent practitioners.