BACKGROUND: This 2-part article reviews the primary research on co-sleeping and bed sharing in maternity units and critiques clinical practice guidelines on co-sleeping and bed sharing in maternity units.METHODS: Electronic search strategies were used to identify primary research and to access clinical practice guidelines about co-sleeping and bed sharing on maternity units. Primary research was reviewed and compared. Clinical practice guidelines were critiqued against the United Nations Children’s Fund (UNICEF; 2004) document, Babies sharing their mothers’ bed while in hospital: A sample policy.FINDINGS: There is little published primary research about co-sleeping and bed sharing in maternity units but that which is available is of high standard. Clinical practice guidelines are more plentiful but vary in quality and scope. The primary research and clinical practice guidelines recognize the positive correlates between co-sleeping and bed sharing and the establishment of breastfeeding and the potential for risks to infant safety. There are differences in the acceptance of co-sleeping and bed sharing between geographic regions. The role of health care providers in educating about the benefits and risks of co-sleeping and bed sharing in maternity units is acknowledged but not well explored.CONCLUSION: Further research on co-sleeping and bed sharing in maternity units is needed to provide evidence to inform clinical practice guidelines.KEYWORDS: infant sleep location; policy development and dissemination; risk assessment; maternal education and behavior modeling; co-sleeping; bed sharing