Undifferentiated fear of left-wing radicalism, defined by its enemies as ‘militant socialism’ or ‘Bolshevism,’ has had important consequences for schools in western societies during certain crucial periods. In the years immediately following the Russian revolution, public education in Britain, North America and Australasia was subjected to intense pressure aimed at making schools assume a greater role in resisting subversion. This pressure, in many instances, was to lead not only to increased instruction in patriotism but also to the systematic monitoring of teacher and pupil loyalty. In the United States many state legislatures instituted loyalty oaths for teachers, while the investigations of the Lusk Committee resulted in the dismissal of teachers suspected of harbouring left-wing sympathies. In New Zealand the introduction of compulsory school flag-saluting and teacher's loyalty oaths during 1921 were roughly contemporary and were similarly motivated. Apart from affording an interesting comparison with larger countries, New Zealand, with its largely centralised education system and small population, was a country where public fear of left-wing radicalism was unhesitantly expressed and where appropriate educational remedies were quickly tried. In particular, this article considers three vital factors which shaped patriotic education in New Zealand schools during the early 1920s: the widespred, generalised public alarm over left-wing militancy; the attempts, largely by professional educators, to shape syllabus requirements to counter the possible subversion of school children; and the Government's increasing willingness to resort to regulation and legislation to weed out disloyal teachers.