•Physiological and psychological effects of viewing a green façade were investigated.•Viewing a green-façade has physiological relaxing effects such as higher alpha wave activity.•Viewing green-façade significantly increased parasympathetic nervous activity and decreased sympathetic nervous activity.•Visual contact with the green-façade positively leads to relaxation and positive mood. Rapid urbanization and the lack of green infrastructure threaten the health of urban dwellers. Green façades have been proposed as a green infrastructure solution to compensate for the loss of green spaces in dense city areas; however, as far as we know, there is inadequate evidence for associations between views of green façades and relaxation. This study aims to clarify the physiological and psychological relaxation effects of viewing a green façade landscape. Twenty-five Chinese females (23 ± 1.5 years) viewed a green façade landscape or a building-wall for 5 min. Data were generated using electroencephalographic, heart rate variability, and skin conductance physiological measures and psychological measures using a semantic differential questionnaire and a Profile of Mood State. Findings suggest that, compared to the viewing of the building wall, the viewing of the green façade resulted in a significant increase in alpha relative waves in the frontal and occipital lobes, a significant increase in parasympathetic activity, and a significant decrease in the skin conductance as well as a substantial increase in comfortable, relaxed, and natural feelings, and a significant improvement in mood state. The green façade appears to enhance human physiological and psychological relaxation compared to the building-wall.