Spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders that are inherited in an autosomal dominant manner. Population studies in certain geographical areas throughout the world indicate that the prevalence of SCA is 3/100 000. SCAs which are characterized by loss of balance and coordination, are progressive and late-onset disorders. Since the clinical symptoms of SCA subtypes significantly overlap, and since there is a high clinical variation even in each SCA subtype, the diagnosis of SCA patients, based on only clinical features, becomes difficult and complex. In this respect, the identification of the genetic etiology of SCAs is significant for understanding and classifying this group of disorders, and for definite diagnosis of patients. Today, molecular diagnosis of at least 12 autosomal dominant cerebellar ataxias with defined genes and mutations is possible. The increase in the number of new ataxia genes suggests the guidance of well-defined clinical signs, neuropathological findings, family history, age of onset and population-specific SCA prevalence in molecular diagnosis. Although there has been no established therapy to prevent the progression of SCA yet, molecular analysis is crucial for the confirmation of clinical diagnosis, the rough prediction of clinical course and family planning. Boğaziçi University experience reveals the importance of clinician–bench scientist cooperation and an intense dialogue for correct and definite SCA diagnosis.