Abstract: Arguably, accessibility to urban open spaces, including parks, is said to contribute to community wellbeing and a healthier urban lifestyle. Accessibility, however, is a complex concept. It is difficult to define and more difficult to measure. While accessibility has now evolved into a multidimensional construct, current open space planning models still use physical proximity to an open space area as proxy variable to evaluate ‘accessibility’. This approach, however, tends to overlook the complexity of the ‘accessibility’ concept. This paper, therefore, proposes an integrative theoretical framework to better illustrate the relationships between open space accessibility and use, within the context of urban open space such as parks. Two processes are described in this framework: (1) a psychological process wherein accessibility to places results from the evaluation of both physical and social- psychological accessibility variables and (2) a behavioural process wherein perceived accessibility influences human behavioural intention to use (or not use) specific urban open spaces. Furthermore, we develop two models to illustrate these processes: (1) an integrated model of open space accessibility containing both spatial and non-spatial dimensions and (2) an expanded planned behavioural model that includes the perceived accessibility construct. These theoretical models provide an alternative framework in gaining a better understanding on the multi-dimensionality of the accessibility construct and its impacts on open space use behaviour.