As matters new stand, cryosurgery has certain definite indications in various fields, either alone or in association with other forms of treatment. It is probably the therapy of choice for 1st-stage haemorrhoids and a series of skin lesions. It is of palliative value in the treatment of tumours and/or an addition to conventional management. The same is true of neoplasm in various sites and stages. As far as the immunological response is concerned, the data available are inconclusive. Further investigation is therefore justified, both experimentally and in man, bearing in mind all the parameters that can be used to assess a possible immune response.