The importance of good history and physical examination with proper interpretation being adequate for neurological diagnosis in as much as 90% of cases cannot be overemphasized. Investigations however are essential for collaboration with or confirmation of the clinical diagnosis. Recent advances in scientific technology have increased the physician's armamentarium in investigative modalities. The advent of these sophisticated modalities (neuro imaging techniques, biochemical and gene studies) for the investigation of neurological disorders has caused an over reliance on these investigations alone for diagnosis. This practice should be avoided as it certainly does not guarantee the correct diagnosis in neurological patients. The aim of the neurologist is to arrive at a final diagnosis by the intelligent analysis of the clinical data aided by the least number of investigations; relevant. In essence, clinical diagnosis should always precede and guide the investigations. In making a neurological diagnosis therefore, it is pertinent to have a thorough clinical evaluation, localize the lesion, make a clinical diagnosis or narrow down the differential diagnosis before requesting investigations. This book 'Fundamentals of Neurological Diagnosis' gives a simplified step wise approach to the diagnosis of Neurological disorders. The first part is a brief anatomy of the nervous system; the second part is a guide to the localization of lesions while the third part details the basic investigations of the central nervous system. It was Ralph Waldo Emerson that said "To ensure that one person breathed easier just because you lived: that is to have achieved". My utmost purpose in writing this book is to ensure that some persons breathe easier in Neurological Diagnosis.