Our health care is facing with the challenges of bed crunch and increasing number of patients with prolonged hospital stay.This study aimed to determine factors contributing to the prolonged hospital stay in a tertiary hospital in Singapore.A random sample of 600 medical records of patients' staying in hospital for more than 21 days was retrieved. The reasons for their prolonged hospital stay were categorized into 'medically unfit' and 'medically fit'.The top three reasons for prolonged hospital stay among the 'medically unfit' group were ongoing medical treatment, surgical interventions and receiving intravenous chemotherapy/radiotherapy. The top three reasons for the 'medically fit' group were waiting for community hospital bed, waiting for a new caregiver and undecided on discharge disposition.The results inform health care stakeholders in planning measures to minimize the incidence of unnecessary prolonged hospitalization for optimal health care resource utilization.Ineffective discharge planning can lead to serious adverse outcomes such as hospital readmission and prolonged hospital stay. Patient navigators have a crucial role in facilitating safe, smooth and timely discharge of patients from acute care hospital to community. Understanding the reasons behind extended hospitalization is essential in order to better provide support.