Archaeobotanical and archaeozoological research about Early Middle Age in Northern Italy testify a very diversified use of vegetal and animal resources. Several types of cereals and legumes are cultivated; fruits and vegetables are grown and at same time spontaneous plant species are collected. Together with the breeding of pigs, goats, sheep and cattle, hunting and fishing are widespread. We discuss the possible causes of the utilization of such a broad spectrum of resources in relation to social and economic factors (such as the political instability, the absence of trade, the population decline). We suggest that the hypothesis derived from archaeobiological data could modify and moreover enrich the hypothesis made on the basis of historical sources.