To provide nurses with an evidence-based Position Statement on the standards patients and visitors should expect when visiting an adult critical care unit in the 21st century in the UK. The British Association of Critical Care Nurses (BACCN) is a leading organization for critical care nursing in the UK and regularly receives enquiries about best practice regarding visiting policies. Therefore, in keeping with the BACCN's commitment to provide evidence-based guidance for nurses, a Position Statement on visiting practices in adult critical care units was commissioned. This brought together experts from the field of critical care nursing and representatives from patient and relatives' groups to review visiting practices and the literature and produce a Position Statement. An extensive search of the literature was undertaken using the following databases: Blackwell Synergy, CINAHL, Medline, Swetswise, Cochrane Data Base of Systematic Reviews, National Electronic Library for Health, Institute for Healthcare Improvement and Google Scholar. After obtaining selected articles, the references from these articles were then evaluated for their relevance to this Position Statement and were retrieved. The evidence suggests a disparity between what nurses believe is best practice and what patients and visitors actually want. Historically, visitors have been perceived as being responsible for increasing noise, taking up space, taking up nursing time, hindering nursing care and spreading infection. The evidence reviewed for this Position Statement suggests there are many benefits to patients and nurses from visitors. There was no evidence to suggest that visitors pose a direct infection risk to patients. Clear visiting policies based on evidence will negate arbitrary decisions by nurses regarding who can visit and will lessen confusion and dispel myths which can only bring benefits to patients, staff and organizations. To make nurses aware of the physical and psychological benefits of visiting to patients. Visitors bring a positive energy to patients and can act as advocates. They can supply nurses with vital information about patients which will enable the nurse to provide more individualized care. Being cognizant of the evidence will help nurses develop policies on visiting which are up to date for the 21st century.