Existing literature indicates peer support is beneficial for people with mental illnesses and plays an important role in recovery. While many studies in the mental health field have focused on formalized peer support within the community, none have explored the experience of peer support among hospitalized patients. The purpose of the current study was to explore the perceptions and experiences of naturally occurring peer support among adult mental health inpatients. In-depth interviews were conducted with ten inpatients across four mental health units, two acute and two long-term. Interviews were transcribed verbatim and analyzed using a qualitative descriptive design. The data show that peer support among inpatients is extensive and beneficial, and occurs independently of staff involvement. The findings illustrate that peer support is a thoughtful process that involves observing, reflecting, taking action, and evaluating outcomes. Supportive actions include helping with activities of daily living, sharing material goods, providing information and advice, sharing a social life, and offering emotional support. This leads to various positive outcomes for providers and recipients of peer support, such as improved mental health outcomes and quality of life. Attempts to provide supportive interactions occur within a particular context, which can hinder or facilitate peer support. The new insights from this study could provide health professionals with an increased recognition of peer support and an appreciation for the unique role patients play in their own and in their peers' recovery. These findings have important implications for establishing collaborative working partnerships with mental health inpatients.