The concept of the 15-Minute City has its roots in past planning theories, but has received increasing attention in recent years, especially following the outbreak of the global pandemic. This emergency situation has highlighted the importance of neighbourhood-based services that can be reached by active travel modes. This work aims to investigate the 15-Minute City concept applied to the city of Lisbon, highlighting its shortcomings, strengths and possibilities for future development. The study is divided into six main parts. The first chapter gives an overview of the 15-Minute City concept dealing especially with its relation to active mobility and is mainly based on scientific publications.