People with severe mental illness (SMI) have considerable unmet physical health needs and an increased risk of early mortality. This cross-sectional survey utilized the Physical Health Attitude Scale (PHASe) to examine the attitudes, practices, and training needs of nurses towards physical health care of people with SMI in three Asian countries (Hong Kong, Japan, Qatar). Cross-country differences were explored and linear regression was used to investigate if nurses' attitudes and confidence were associated with their level of involvement in physical health care. A total of 481 questionnaires were returned. Hong Kong nurses were less involved in physical health care than those from Japan and Qatar. Nurses' attitudes and confidence were significant predictors of their participation in managing physical health. Compared with western countries, more nurses in this study felt that mental illness was a barrier to improving physical health. Three-quarters reported that they needed additional training in promoting cardiometabolic health. The perceived need for additional training in physical health care was held by Mental Health Nurses (MHN) irrespective of their type of nursing registration and nationality. Nurse educators and service providers should reconsider the physical health care training requirements of nurses working in mental health settings in order to improve the physical health of people with SMI.