IN 1962, rolling disease appeared epidemically for the first time among the laboratory rats of the Research Laboratories of the Finnish State Alcohol Monopoly (Alko). (By reason of the vague aetiology of the disease, the term “rolling disease” is used here in preference to “labyrinthitis”. The symptoms described for these two, possibly different, diseases are almost the same.) Within a short period, the disease developed into a serious problem, particularly in genetic experiments, and in experiments involving long-term administration of alcohol. In the trials made to save scientifically valuable material, use was made of penicillin, a mixture of streptomycin and sulpha, and tetracycline. Of the treatments, that with tetracycline was found to be the most effective. Similar observations have been published by Dolowy et al.1 but their report seems to be little known, and there seems to be justification for a brief presentation of our observations, with some notes on the disease.