Multiple sclerosis (MS) is an autoimmune disease characterized by neuroinflammation and neurodegeneration in the central nervous system. The disease affects the white matter, cortex and deep gray matter of the central nervous system and is characterized by inflammatory-demyelinating lesions and neuronal/axonal degeneration. Demyelination associated with these lesions and the accompanying axonal degeneration are responsible for neurological disability in MS. There are many scales and mobility and functional performance tests in the literature to assess balance, such as the Sit Reach Test, Timed Up and Go (TUG) test, Tinetti Performance Oriented Mobility Assessment (POMA), Berg Balance Scale (BBS) (5) and Balance Evaluation System Test (BESTest). The most appropriate balance assessment scales for individuals with MS are those that assess static and dynamic sitting balance while standing and dynamic balance only. Since balance in individuals with MS is a dynamic process that changes gradually, new measurement methods that can record these changes and determine the appropriate treatment for these variables are needed. The Dubousset Functional Test (DFT) was developed by Dr. Jean Dubousset as a four-component practical assessment to evaluate the physical function and balance capacity of individuals with spinal deformity. The DFT consists of four components: getting up from an armless chair and walking 5 meters forward and backward, ascending and descending steps, transition from standing to sitting position, and gait assessment with a dual task test (counting backwards from 50). The difference of this test from the others is that it evaluates the spinopelvic muscle groups that are directly related to functionality, maintains the global trunk alignment of the individual and provides objective results about functional performance and balance. In addition, unlike other functional performance tests, the DFT assesses the neurophysiological effects of the process that requires individuals to perform two tasks at the same time by measuring their coordination, balance, attention and thinking skills during functioning through a dual task component. The validity and reliability of this test has been previously investigated in low back pain, stroke, parkinson's disease, elderly individuals and hemiplegia. In this study, it was aimed to examine the validity and reliability of the Dubousset functional test in individuals with multiple sclerosis.