Introduction. The hereditary ataxias in Cuba make up the highest concentration of these patients in the world. The spinocerebellar ataxia type 2 (SCA2) molecular form is predominant. Objectives. To determine the patients and incidence of hereditary ataxias. Patients and methods. We made a descriptive study of 440 patients and 1,633 members of families at risk from this disorder in the province of Holguin, We calculated the prevalence rate and incidence. Results. The rate of prevalence of patients in the province is 43 cases per 100,000 inhabitants; the highest rate was 503 cases per 100,000 inhabitants in part of the municipality of Baguanos. The age group that M ns most affected was that of 30-39 years, with a prevalence of 63.97 cases per 100,000 inhabitants. The rural population shotted the highest incidence (62.04 cases per 100, 000 inhabitants). The risk of members of affected families showing the disorder was 159.33 cases per 100, 000 inhabitants in this province. The highest incidence was 18.08 cases per 100, 000 inhabitants in Cacocum, where the incidence in the province was 4.39. Conclusions. On average the disorder passes from one state to the next every year, which suggests that the extent of the disorder worsens with time. The prevalence and incidence are the highest in the world. This together with the dominant pattern of inheritance, the effect of anticipation and inexorably progressive course of tire disorder shows the serious health problem that affects the Eastern region of Cuba.