Absconding by patients from acute psychiatric care poses a significant problem to professional staff, and can involve significant risks for patients and others. This paper describes the methodology of a major prospective study of absconding recently completed in the East End of London, and reports the findings on why patients abscond from hospital. Interviews with 52 patients who returned to their wards showed that they abscond because they are bored, frightened of other patients, feel trapped and confined, have household responsibilities they feel they must fulfil, feel cut off from relatives and friends, or are worried about the security of their home and property. Psychiatric symptoms also contribute to the decision to leave, but in nearly every case patients can give additional and rational reasons for their abscond. Some patients leave impulsively and in anger following unwelcome news about delayed permission for leave or discharge. Others leave specifically in order to carry out some activity outside the hospital. In order to reduce absconding and rejection of care, nurses may need to carefully consider the meaning admission has for patients, and the impact it can have upon their everyday lives.