Many aspects of meditation have been examined for over seventy years, including its physiological, psychological variables, and clinical conditions. However, the effectiveness of Zen meditation for clinical application has been debated. The quality of meditation could be one of the keys to understand the disagreements among studies. This study aims to reveal the experience of Zen meditation among participants with generalized anxiety disorder (GAD). A psychiatric outpatient department at a Taiwanese medical centre was the study site. A six-week Zen meditation programme was designed and provided to the study participants. Multiple data collection methods were used, including interviews, field notes, and diaries. Merleau-Ponty's phenomenology was adopted as a framework for guiding the data interpretation. Investigator and method triangulation was used to enhance the study rigour. Twenty-one adult patients with GAD were recruited. Four categories were merged: First, bodily awareness referred to the participants becoming more sensitive to their bodies, such as when they felt muscle tension, and when their senses became more sensitive. Second, determining the characteristics of the GAD body revealed how participants identified their bodies. Third, being with the breath referred patients to a wholly concentrated state. Finally, bodily resistance referred to the body disagreeing with the physical activities when practicing. By practicing Zen meditation, the participants experienced being close to their bodies, learnt to stay quietly with their bodies for a while, and gained awareness of their bodies. The contribution of this study is to identify the essence of good quality of Zen meditation which should be considered before examine the effect of Zen meditation.