BackgroundThe increasing number of chronic diseases consumes a large amount of health resources and puts a huge burden on health service system. The integrated management of chronic diseases in Sanming City aims to improve the efficiency and quality of chronic disease management through the collaboration between different levels of medical institutions.AimThe aim of the present study was to use the theory of planned behaviour (TPB) to examine the intention and behaviours of interinstitutional collaboration in chronic disease management (ICCDM) among healthcare personnel.MethodsA cross-sectional study of 274 health care personnel was conducted in medical institutions in Fujian Province, China, from March 2022 to April 2022. A self-administered questionnaire based on TPB theory was applied to measure the participants’ ICCDM behaviours.ResultsThe proposed TPB model revealed that attitude was significantly and positively associated with behaviour intention, and behaviour intention and perceived behavioural control were significant predictors of ICCDM behaviour.ConclusionTPB provides insights into ICCDM behaviour. Due to the fact that attitude, perceived behavioural control, and behavioural intention towards ICCDM behaviour were demonstrated to be significant predictors of ICCDM behaviour, these factors may be a promising focus of ICCDM interventions in the integrated management of chronic diseases in China.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12913-023-09453-0.