The need and values of patient- and family-centred care (PFCC) have been globally increasing in the health care landscape. However, the concept of PFCC and the components in adult intensive care units (ICUs) remain wide-ranging. To elucidate the core concepts of PFCC interventions and evaluate the effects of the interventions in adult ICUs. We searched electronic databases (PubMed, Cochrane Central, CINAHL, EMBASE, PsycINFO, RISS, KMbase and KoreaMed) from inception to 20 June 2022, for all studies on PFCC interventions. Three authors independently conducted data screening and extraction. The core concepts and the effects of PFCC interventions in adult ICUs were examined. The effects of patient- and family-centred care interventions in adult ICUs were examined. The quality of the included studies was evaluated using the Mixed Methods Appraisal Tool. Overall, 3507 records were identified, and 14 full-text articles were assessed. Participants in the included studies were patients and/or their family members in adult ICUs. The main concepts of the studies were participation and information-sharing. Only two studies used collaboration as the main concept of intervention. PFCC interventions have shown positive outcomes for patients, including increased satisfaction, improvement of patient health status and reduced incidence of complications. They have also been beneficial for families, leading to higher satisfaction levels and decreased anxiety. Additionally, these interventions have positively impacted health care providers by enhancing satisfaction and improving rounding efficiency. Moreover, they have influenced health care utilization by decreasing hospital costs and length of stay. This review highlights the advantages of PFCC interventions for patients, families and health care providers in adult ICUs. Future research should focus on developing strategies to incorporate collaboration more comprehensively as a core concept in the implementation of PFCC interventions. Future research endeavours must prioritize collaborative efforts involving health care providers, patients and their families by deploying an array of strategies within the intensive care unit setting.