Impact of COVID-19 lockdown on agrobiodiversity, organization of farm work and food security in Mexican rural areas. COVID-19 has hit Mexico very hard, forcing the Mexican government to institute lockdowns. The lockdown reduced employment opportunities and forced farmers to stay in their hometowns. The economic impact on COVID-19 is starting to be addressed by scholars from an empirical point of view. However, the transformations induced by the lockdown on Mexican rural areas, especially on the organization of farm work and agrobiodiversity, are still unknown. Local crops and local practices remain a pillar of the agricultural systems in Mexico. In this paper we address several entangled questions: How do the consequences of COVID-19 influence farmers’ practices? What is the impact of the lockdown on farmers' choices in terms of crop diversity? We present the results of a multisite project (Puebla, San Luis Potosí, Mexico City, Yucatan, Oaxaca and Chiapas) whose aim was to analyze challenges and transformations in Mexican rural areas during the 2020 lockdown. We compared farmer agricultural and food practices as well as crop diversity cultivated in 2019 and in 2020, before and during the lockdown. We analyzed how COVID-19 affected certain trends and dynamics such as: local markets, seed networks, local organization of labor, and agricultural practices. The livelihood of rural people is largely dependent on off-farm jobs outside their community. Understanding how they dealt with the changes imposed by COVID-19 is crucial to contribute to actions fostering the resilience of farmer agriculture.