Each round of agricultural censuses covers a ten-year period. The present round (WCA 2020) covers agricultural censuses to be undertaken between 2016 and 2025. The census of agriculture continues to play a key role in the collection of structural data on the agriculture sector. The WCA 2020 will ensure that data collected are comparable at the international level while also addressing emerging information needs of the 21st century. Four modalities for conducting a census of agriculture are envisaged: the classical (one-off) approach, which is still widely used; the modular approach, which was introduced in the WCA 2010; the integrated census/survey modality, involving rotating survey modules over the years between two censuses; and the combined census modality, which uses administrative data. The concept of ‘essential’ items is re-introduced and ‘frame’ items are now separately identified for those countries wishing to adopt the modular approach or follow-up surveys. The programme emphasizes the benefits of the developments in information technology for census data collection, processing and dissemination. This publication provides guidance on agricultural censuses carried out by countries in the period between 2016 and 2025. The WCA 2020 will ensure that data collected are comparable at the international level while also addressing emerging information needs of the 21st century.