A comparison has been made among some methods (concentration on aluminium hydroxide precipitates, polymer two-phase separation, cellulose membrane filtration, direct inoculation) for virus isolation from raw sewage. The concentration on aluminium hydroxide has given significantly better results than the other methods. No significant differences have been noted between the two-phase separation and direct inoculation method. The membrane filtration method has given no positive result. All isolated viruses belonged to the adenovirus group.