Aflatoxins are a group of mycotoxins that pose risks to human and animal health due to their high toxicity and carcinogenicity. They are produced by 28 different species within sections Flavi (22 species), Ochraceorosei (2), and Nidulantes (4) of the fungal genus Aspergillus (A). Rapid detection of aflatoxin-producing fungal species may aid the food industry to assess potential risks associated with commodities. Species-specific LAMP assays were previously developed for the detection of the most common aflatoxin producers, i.e., A. flavus and A. parasiticus. However, these assays are too specific and therefore fail to detect species that occur less frequently. This chapter describes the development of a group-specific LAMP assay targeting the aflD (= nor1) gene in all aflatoxin-producing species within section Flavi of the genus Aspergillus. Detection of positive LAMP reactions under daylight conditions was facilitated using neutral red as visual indirect in-tube signal indicator. The assay was characterized for specificity and sensitivity using purified genomic DNA. A protocol involving minimal sample preparation was developed and applied to the analysis of pure culture spore solutions and to the detection of aflatoxinogenic fungi in naturally contaminated commodities with rice given as an example.