During the 19th century, the process of establishment of geology as a scientific discipline was reinforced also by the general acceptance and codification of the role of systematic fieldwork within textbooks for students and 'geological guides' for amateurs. The beginning of this trend may be traced not only in the practices of the travelling 'oryctologists', mineralogists and mining experts of the second half of the 18th century, but also in the early examples of scientific instructions for geological travellers. In his book in 2 volumes Guide du géologue voyageur (Paris, 1835-1836), Ami Boué (1794–1881), one of the founders of the Société géologique de France in 1830 and himself a great traveller, was in fact inspired by De Saussure's Agenda (1796) and Leonhard’s Agenda Geognostica (1829), to write a long detailed chapter Préparatifs et instructions préliminaires pour les voyages geologiques (Boué 1835–1836, vol. 1, p. 9–158). He believed that his 'geological guide' could be easily used also by general readers and 'amateurs de la géologie', although a part of the first volume and the full content of the second volume could be regarded as a real textbook. The Guide du géologue voyageur can be considered a complete work for travelling geologists, with a specific text of very elaborate and detailed instructions. This was because Boué was also trying to organize and in some way propose a first codification of the activities and the correct procedures to be adopted by the geologists in the field. The aim of this paper is to analyze in detail the concept and the methodology of geological fieldwork expressed by Boué in his work, as well as to make a comparison with the contemporary geological literature and the early outlines of field-geology.