We report 425 myasthenic patients who underwent thymectomy during thelast 15 years. The authors analyse the results of thymectomy in separategroups, including thymomas (12.7%), childhood myasthenia (9.4%) andcombined cases (12.4%). They evaluate the results according to theDisability Status Scale based on a points system. Three series wereevaluated: patients operated upon between 1972-1977, 1977-1982 and1982-1987. Although the results in all three series were good, there hasbeen steady improvement over the years. Childhood myasthenia gravis gavethe best results but thymectomy was beneficial in the combined(immunological) group, in long-lasting myasthenia and in thymomas. Factorsinfluencing the results of thymectomy were patients' age, time intervalbetween onset of disease and thymectomy, resistence to therapy and thymictumour. Thymic activity as reflected in germinal centres can also influencethe results: the more active the thymus, the better the results.