This research addresses how homelessness services from the statutory and voluntary sector are working for people with complex needs in the City of Edinburgh. Using a qualitative approach, it analyses the service providers’ perspectives on the concept, challenges and what works when dealing with this group of people. It also explores the opinions of a sample of service users, categorised as having complex needs, regarding the accommodation and support they are receiving. After analysing the data, it is argued that homelessness agencies do not have an appropriate cognitive nor institutional framework that facilitates an effective approach to work with people with complex needs. The lack of a sophisticated understanding that recognises the relational difficulties of individuals and the presence of structural, organisational, professional and interpersonal barriers hinder the development of positive long-term relationships which is considered as the key factor of change. For this reason, it is recommended to address a set of factors that go beyond simplistic and linear approaches and move towards complex responses in order to tackle homelessness from a broader perspective and, ultimately, achieve social inclusion.