Ten patients with trichiasis were treated with cryosurgery by the standard retinal probe with nitrous oxide. A double freeze-thaw method was used. Nine of the patients had trachomatous trichiasis and one had conjunctival scarring. In only the latter case were the lashes destroyed, and these grew again after 2 months. Trachomatous trichiasis is frequently associated with entropion. The tarsal plate in such cases is often thickened and distorted, with extensive conjunctival scarring. The success of cryosurgical treatment of trichiasis depends not only on the type of probe used but perhaps also on the aetiology of the disease. To our knowledge no similar trial of this form of treatment of trichiasis has been carried out in eye centres in Africa south of the Sahara. Cryosurgery is simple to perform and of great potential use, particularly in areas where there is a shortage of skilled surgeons to perform the delicate eyelid operations often required in trichiasis.