The growing demand for food production and the global developments regarding the intensification and mechanization of agriculture are likely to affect material use in the agricultural sector in some way in the future. This study addressed a research gap regarding the current and future material requirements of the global agricultural system, and it represents a first attempt to estimate the size and composition of the current global material stock embedded in agricultural field machinery. The study also explored the potential future developments of this material stock in five Shared Socioeconomic Pathways (SSPs) through a material scenario analysis, which utilized scenario data generated by an integrated assessment model IMAGE. Available country-level data on the number of machinery in use was linked to agricultural production data through the calculation of ‘mechanization factors’, which describe the relationship of the size of the in-use machinery stock and the annual production quantities of a country. Regionally aggregated mechanization factors were used in combination with regional production data for the estimation of the total numbers of different field machinery currently in use in 26 world regions. These numbers were combined with literature-based estimates of the average material compositions and masses of different types of agricultural field machinery to quantify their current in-use material stocks. Steel (121 Mt), ductile iron (86 Mt), and rubber (21 Mt) were identified as the largest global material stocks of agricultural field machinery, and the largest shares of the materials were found in tractors and combine harvesters. The results of the quantification of the current material stock were incorporated in a material scenario analysis in combination with IMAGE scenario data on agricultural production in the different SSPs. The scenario analysis involved two scenario models with distinct assumptions concerning the development of mechanization levels over time. Depending on the SSP scenario and the model assumptions, the results of the scenario analysis indicated a 50 to 200 percent growth in the global material stock of agricultural machinery by the year 2100. While the scenario analysis assumed the current agricultural practices and technologies to maintain their importance in the future, the study also explored some newer developments taking place in the global agricultural system and the ways they might influence the material stock of agricultural machinery in the future.