In this research, the development of cross-sector collaboration that can enable working together towards systems change was explored. In the recent years, the number of cross-sector collaborations has grown exponentially. However, the high failure rate in cross-sector collaborations in the planning phase raised questions that this study set out to explore. The framework of this study constitutes of challenges and success factors of cross-sector collaborations, leadership in cross-sector collaborations, collaborating for systems change and sustainable development. Research approach used in the study was qualitative research that used exploratory approach. A case study strategy was chosen in order to best serve the purpose of this research. Forward Malmö collaboration was chosen as a case study in order to evaluate existing theories and explore new themes and patterns. The study discovered that the crucial key factors in collaborations are interdependence, commitment, trust, coordination, reinforcing activities, continuous communication, common agenda, shared measurement and joint problem-solving. It was also found that Forward Malmö aims to deal with systemic causes of societal challenges because the current system is unable to handle them. The reason behind initiating the collaboration was to find new ways of collaborating across different sectors that leads to a systemic change. The representatives of the organizations joined out of self-interest to work across boundaries to solve challenges together. However, the research also identified challenges within Forward Malmö such as difficulties in getting new members to commit to the collaboration and get financial support due to the uncertain future of the collaboration. Differences in perception were found especially regarding the level of structure and formalization in the collaboration. Organizational change was perceived as important when it came to collaborating to meet the needs of the society. The role of leaders was raised as an important aspect in the collaboration and the need for a flexible leadership approaches was identified in the study. Integration of sustainability in the collaboration was also raised in the study and the findings showed that Forward Malmö is mostly planning to focus on social sustainability questions in relation to co-producing sustainability outcomes for the city. The researchers provided recommendations for future research, that were yielded from the outlined findings of this study. Key words: Cross-sector collaboration, systems change, leadership, sustainability, structure, formalization.