This article investigates the extent to which residential gardens affect human welfare in Istanbul (the European side). The developing technology, population growth, and immigration are factors which expose the city of Istanbul to intense construction. Consequently, the gardens in the houses located at the center of Istanbul are decreasing day by day, limiting outdoor activities for the residents, and affecting them physically and mentally. In this study, a questionnaire was applied to 400 people in Istanbul’s European side to investigate the extent to which residential gardens affect human well-being. These questionnaires were applied according to five-point Likert scales and the results were analyzed in the SPSS program by applying correlation analysis. The data obtained from the applied questionnaires were analyzed in the SPSS program. As a result of the analysis, it was concluded that residential gardens have a positive influence on the physical and psychological development of people, and also contribute to the protection of nature and biological diversity. Statistically, it has been determined that people mostly use their gardens in the summer months (49.30%) and on the weekends, and spend an average of 0–2 hours (57.50%) in their gardens. In addition, these analyses were associated with participant characteristics such as age (18–25, 26–30, 31–40, 41–50, 51–60, 60 and older), gender (female/male), socioeconomic status (occupation and income) and social demography (change in population). As a result, this study showed that residential gardens in urban areas contribute significantly to people and nature, that more garden areas should be added to the residences to be built in urban areas, and that these areas should be designed in a functional and sustainable way for people to benefit from nature in the best way.