Background/Objectives: Clinical reasoning is an essential competency for all healthcare practitioners, particularly in the context of neurological rehabilitation, where patient management is complex and multifactorial. This paper proposes a unified framework for clinical reasoning in neurological physiotherapy, integrating the aspects of physical function with the World Health Organization’s International Classification of Functioning, Disability, and Health (ICF). Methods: The proposed framework incorporates a biopsychosocial approach, focusing on a patient-centred and goal-oriented methodology that allows for a comprehensive evaluation of the patient’s needs across multiple domains, including body functions, activities, and participation. By integrating clinical reasoning theories from various disciplines, this framework seeks to enhance the decision-making process and improve communication among healthcare professionals. Results: The model provides a systematic approach to assessing and addressing deficits in motor control, sensory functions, and other aspects of neurological rehabilitation. This work highlights the importance of interdisciplinary collaboration and emphasizes the role of physiotherapists in managing neurological impairments. Conclusions: The Biopsychosocial Reasoning Approach In Neurophysiotherapy (BRAIN) framework aims to improve functional outcomes by offering a more adaptable, multidisciplinary, and evidence-based approach to clinical reasoning in neurological physiotherapy.