Few school principals or teachers of extended experience fail to realize the need among their pupils for some sort of instruction and guidance in matters pertaining to sex. Undoubtedly this realization has led to the many spontaneous attempts to introduce sex instruction into high schools. Experiments have sprung up all over the country, a few proved to be ineffective because they were undertaken by a teacher unsuited for the task. Most of them were successful enough to win approval of both school officials and the public. In January, 1920, the United States Bureau of Education and the United States Public Health Service sent out a questionnaire to obtain information regarding the status of sex instruction in the high schools of the United States. This questionnaire was sent to 12,025 accredited and partially accredited high schools and brought 6,488 (53.8 percent) replies. Its purposes were threefold: (1) To ascertain facts about the number and distribution of high schools giving sex instruction through the regular subjects of the curriculum; (2) to learn of the content and method of the parts of such school subjects as related to sex Instruction and guidance; and (3) to discover the attitude of principals toward sex instruction in high schools. The schools from which replies were received fall naturally into three groups: (1) those schools giving emergency sex education i.e. through lectures, occasional talks, sex hygiene exhibits, pamphlets etc.; (2) those schools giving integrated sex education, i.e. incidentally in the subjects of the regular curriculum; and (3) those schools giving no sex education. Even though progress has been made in sex instruction in high schools and there are large numbers of principals favoring and undertaking it, principals would do well to continue to be cautious. The figures given should not perhaps be interpreted too literally. The best of questionnaires are difficult to interpret, and it is possible that some principals did not actually mean to imply that such definite instruction was being given as their answers would indicate. The Bureau of Education and the Public Health Service are following up the replies to these questionnaires in order to secure more exact information and further details about methods used. In this way experience of schools succeeding in such new and difficult work will be made available to others wishing to inaugurate new efforts in this direction and will furnish a sound basis for further developments in sex Instruction. (Contains 4 tables.)