Albeit the importance of the urban parks to serve as physical, physiological, and health relief platforms, little attention has been paid to the study of the adult’s preferences of outdoor recreational activity that is based on the human stress level. Therefore, the aim of this paper is to unveil the preference for outdoor recreational activity according to the human stress levels. Accordingly, this paper adopts a quantitative method through a web-based questionnaire survey that rests upon Kuala Lumpur’s urban population as the representative sample. The questionnaire consists of three parts- personal data, the preference of outdoor recreational activity, and a self-reported health status. This paper reveals from a pilot study of 62 respondents only, as the actual questionnaires’ survey and data analysis are still in progress. The data was analysed using factor and descriptive statistics in order to identify the most preferred outdoor recreational activity by a stressed adult. The result showed that the 20 items of outdoor recreational activities load into two dimensions, i.e., passive activity and active activity. The preferred passive activities by the adult who is reporting stress are enjoying the peace, resting and relaxation, enjoying the fresh air, releasing stress, enjoying nature, enjoying the sun and the sound of birds. For active activities, most of the adults who are reporting stress prefer to jog and do brisk walking. Significantly, the study’s findings enlighten the urban park planners - including the landscape architects, to design parks for outdoor recreation that could correspond and accommodate the different levels of stress.