Administrative staff at healthcare facilities, who are not either doctors or nurses, coordinate, facilitate patient care, and account for 18–20% of human resources in hospitals. Their contribution to the value chain of healthcare service is crucial, but they are not well recognized either by hospital managers and healthcare staff or by patients. Low recognition may cause low job motivation and repeated tasks may cause boredom for them. Our study aimed to assess the level of job motivation among administrative staff in 2 hospitals of Ho Chi Minh city, Vietnam, and explore the influencing factors to job motivation. The exploratory mixed methods design was used in our study with an initial quantitative study with a designed questionnaire and then followed by a qualitative study with focus group discussions. The job motivation index of the administrative staff in our study was not high (4.0). Positive factors were extra income, higher education, healthcare benefits, and a good working environment. Negative factors were low salary index, less chance of higher education, and no separated key performance indicator criteria. The low job motivation index of the administrative staff at public hospitals in our study warns of the negative impact on hospital income in terms of patient satisfaction. In the future, hospitals should have a new strategy in human resource management specifically for administrative staff by maintaining the positive factors and step-by-step overcome the negative factors such as developing separated key performance indicator criteria.