The aims of this study were to describe the current status of intensive care unit (ICU) visiting hours policies internationally and to explore the influence of ICUs' open visiting policies on patients', visitors', and staff perceptions, as well as on patients' outcomes. A review of the literature was done through MEDLINE, EMBASE, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. The following keywords were searched: "visiting," "hours," "ICU," "policy," and "intensive care unit." Inclusion criteria for the review were original research paper, adult ICU, articles published in the last 10 years, English or Italian language, and available Twenty-nine original articles, mainly descriptive studies, were selected and retrieved. In international literature, there is a wide variability about open visiting policies in ICUs. The highest percentage of open ICUs is reported in Sweden (70%), whereas in Italy there is the lowest rate (1%). Visiting hours policies and number of allowed relatives are variable, from limits of short precise segments to 24 hours and usually 2 visitors. Open ICUs policy/guidelines acknowledge concerns with visitor hand washing to prevent the risk of infection transmission to patients. Patients, visitors, and staff seem to be inclined to support open ICU programs, although physicians are more inclined to the enhancement of visiting hours than nurses. The percentages of open ICUs are very different among countries. It can be due to local factors, cultural differences, and lack of legislation or hospital policy. There is a need for more studies about the impact of open ICUs programs on patients' mortality, length of stay, infections' risk, and the mental health of patients and their relatives.