This article identifies the factors that characterise effective interpersonal partnerships between teachingassistants (TAs) and teachers working in inclusive schools in Catalonia (Spain). This phenomenologicalstudy, based on 40 semi-structured interviews with 22 TAs and 18 teachers revealed that the maininterpersonal factors affecting partnerships were: feeling at ease; trust; respect; and valuing one another.Participants detailed key aspects such as personal affinity, professional compatibility, open communi-cation, a sense of belonging to a class-group, and teamwork, as additionally important for successfulpartnerships. Thefindings provide insight into how schools can support the development of effective TA-teacher partnerships. Implications are discussed.