GRANDPARENTING PRACTICES AND THEIR ASSOCIATION WITH PHYSICAL AND MENTAL WELL-BEING AMONG OLDER ADULTS WITH CHRONIC DISEASES IN MALAYSIA: A CROSS-SECTIONAL STUDY Introduction: There is limited understanding of the association of grandparenting with the wellbeing of older adults with chronic diseases. This study aimed to examine grandparenting practices and their association with physical and mental well-being among older adults. Methods: The cross-sectional study was conducted at an outpatient clinic in a tertiary hospital in the Klang Valley, Malaysia. A total of 421 older patients with grandparenting experience were interviewed. The SF-12 Version 2.0 Health Survey was utilised to assess mental and physical wellbeing. Sociodemographic information, chronic disease care and grandparenting practices were evaluated to investigate any potential relationship with physical and mental well-being. Results: Of the participants, 80% were aged 60–74 years; 62.5% were women; and 81.4% completed secondary education. More than half of the participants voluntarily took on the role of grandparenting. The participants showed an impaired physical function but a preserved mental wellbeing. Never missing regular medication due to grandparenting and taking up grandparenting based on the circumstances were related to mental health. However, no factor was significantly associated with physical well-being. Conclusion: Two factors are linked to improved mental well-being. In contrast, there is no significant relationship found between a decline in physical health and grandparenting practices. Further research is needed to determine the causal relationship between physical health challenges and grandparenting practices.