SummaryTwo hundred and sixty-nine patients suffering from acute gonococcal urethritis were treated with single oral doses (variable) of a triple tetracycline preparation (‘Deteclo’).In acute uncomplicated gonorrhoea, it was found that a single-session treatment with 1.2g. 'Deteclo' gave a failure rate of 6.2%. Side-effects were of a gastrointestinal nature and were not a serious hazard at that particular dosage. They were minimised by an antiemetic, viz. promazine hydrochloride or metaclopramide mono-hydrochloride.It would appear, therefore, that 'Deteclo' has all the advantages of any oral preparation which can be used in a single-session treatment of acute uncomplicated gonorrhoea. It should, therefore, be considered in this light as an effective, convenient, alternative treatment in uncomplicated male gonorrhoea.Because of frequent and often distressing side-effects, it was not possible to arrive at an acceptable single-session regime using 'Deteclo' in non-specific urethritis.