This review covers, for the first time, all methods based on the use of
Aspergillus
strains as biocontrol agents for the management of plant diseases caused by fungi and oomycetes. Atoxigenic
Aspergillus
strains have been screened in a variety of hosts, such as peanuts, maize kernels, and legumes, during the preharvest and postharvest stages. These strains have been screened against a wide range of pathogens, such as
Fusarium
,
Phytophthora
, and
Pythium
species, suggesting a broad applicability spectrum. The highest efficacies were generally observed when using non-toxigenic
Aspergillus
strains for the management of mycotoxin-producing
Aspergillus
strains. The modes of action included the synthesis of antifungal metabolites, such as kojic acid and volatile organic compounds (VOCs), secretion of hydrolytic enzymes, competition for space and nutrients, and induction of disease resistance.
Aspergillus
strains degraded
Sclerotinia sclerotiorum
sclerotia, showing high control efficacy against this pathogen. Collectively, although two
Aspergillus
strains have been commercialized for aflatoxin degradation, a new application of
Aspergillus
strains is emerging and needs to be optimized.