Introduction Children with special needs are children who are at risk or have physical, developmental, behavioral, or emotional conditions that require health and related services in a type or amount that is beyond the needs of children in general [1]. To meet the needs of care, education, and rehabilitation of these children who depend on their families in every aspect of daily life is a long, tedious, and challenging process [2,3]. Having a child with special needs affects the roles and responsibilities of the family. Family members try to adapt to the stress, physical effort, role and identity changes, and financial and psychological problems that arise as a result of the child's health status. They also undertake responsibilities such as interacting with various professionals including physicians, physiotherapists, occupational therapists, and special education specialists; providing environmental modifications, equipment, or assistive devices; and supporting skill training and other intervention programs [3-5]. Families know their children well and want the best for them. A supportive family and society positively influence the child's functioning, quality of life, and social participation. Parents are constantly in contact with health professionals and are part of the team in choosing, implementing, and maintaining education and treatment programs for children with special needs. Especially in recent years, it has been emphasized that family has an important role in understanding and meeting the needs and abilities of children with special needs [5,6]. Family-centered approaches that increase the quality of life of the child, as well as the quality of life of the family, have gradually become the focus of pediatric rehabilitation. Family-centered practice is a dynamic process that adapts to the changing situation, needs, and priorities of the child and the family. These interventions enhance the child's physical, emotional, social, and cognitive functions; promote meaningful activities and social participation and improve engagement in treatment programs; and Background/aim: The present study aimed to develop a reliable and valid assessment tool for measuring family functioning in rehabilitation. Materials and methods: Semistructured interviews were performed with 100 rehabilitation professionals working in pediatrics to identify the feature to be measured. The items determined with the qualitative analysis of the data were presented to 14 experts and content validity was provided. The questionnaire created based on the judgments of the experts was administered to 440 parents of children with special needs. Results: After validity and reliability analysis, the final version of the questionnaire comprised 48 items with four factors identified as awareness, attitude and behavior, social participation, and engagement in rehabilitation. These factors explained 49.94% of the total variance and the factor loadings ranged from 0.492 to 0.773. Internal consistency reliability calculated with the Cronbach alpha coef...