Technical Abstract: Allicin is the chief anti-microbial compound produced in garlic. It has been extensively studied for activities against human and food-born pathogens. In this study, the antimicrobial activity of allicin (Allisure (TM) Liquid) was tested against a number of bacterial and fungal pathogens (Paenibacillus larvae subsp. larvae, Paenibacillus larvae subsp. pulvifaciens, Acosphaera apis and Ascosphaera aggregata) associated with social and solitary bees. The minimum inhibitory concentrations (MIC) of allicin were determine using broth microdilution method in the range of 1000 ppm to 0.25 ppm. Allicin liquid showed activity against gram-positive bacterial isolates (MIC 350 ppm) and fungal isolates (MIC 250 ppm). The anti-microbial activity of allicin was also tested in an agar diffusion test using 250 ug of allicin per disk. Bacterial isolates (P.l. pulvifaciens and P.l. larvae) produced a zone of inhibition in the range of 31-35 mm (A. apis) and 35-37 mm (A. aggregata). The macroslide class antibiotic tylosin (Tylan 50, Elanco Inc., IN) was used as a control in both the MIC assay and in the agar diffusion test. The data from this study point to the potential of allicin to inhibit growth of bee pathogens and prevent occurrence of the two major bee diseases.