The first edition of the Regional Handbook to the Northern Highlands was published in 1936; for the subsequent editions in 1948 and 1960 the text was uppdated, but not extensively revised. Since that time there has been a tremendous increase in research into all aspects of the geology of the Northern Highlands and it has become necessary to produce a completely new text. The present handbook gives a fuller treatment of the geology of the Outer Hebrides than the previous editions, and of the deep structures of the crust beneath le Northern Highlands. Unfortunately, lack of space has permitted only brief references to the geology of the seas around northern Scotland; it is hoped that this will be treated in more detail in another publication.