The meniscusganglion of the knee is rare but it's an indication for the operation, because it is painful and in the most cases it is connected with an injury of the meniscus. Between 1987 and 1992, 23 patients with meniscusganglion were operated only with the method of the inner drainage. There was no recurrence. We have seen that the concept of the arthroscopy of the knee with the inner drainage of the meniscusganglion is an easy and effective treatment with all the advantages of the arthroscopy.