To ensure a safe transition of mental health patients from hospital to community settings, greater attention is being given to discharge planning. However, assessing the quality of discharge planning has been challenging due to wide variations in its definition. To facilitate evaluation of discharge planning, its meaning in the mental health literature was systematically explored. This concept analysis is part of a larger study to develop an instrument to measure the quality of discharge planning processes in mental health care. Walker and Avant's (2011) concept analysis approach was adopted to provide a comprehensive definition of discharge planning. Electronic databases and grey literature were searched and analysed according to Grant and Booth's (2009) systematic search and review process. Literature published between 1900 and 2018 was reviewed. Forty-nine articles meeting the inclusion criteria were included in the analysis. Discharge planning is a complex, multifaceted concept with six defining attributes: comprehensive needs assessment; collaborative, patient-centered care; resource availability management; care and service coordination; discharge planner role; and a discharge plan. Discharge planning begins with the initial rapid assessment and symptom stabilization of a patient on admission, coincides with treatment planning, and is associated with hospital readmissions and continuity of care. The mental health literature was reviewed to analyse different interpretations of discharge planning. The conceptual definition provided can assist healthcare providers, organizational leaders, and policymakers to design and implement effective discharge planning policies and guidelines. Providing clarity regarding discharge planning also provides a critical foundation for developing an instrument.KEY WORDS: health services administration, mental health services, patient discharge, psychiatric nursing, qualitative research.