This book begins by examining how the cultivation of garlic (Allium sativum L.) has social and economic importance in various regions of Venezuela, particularly focusing on the research carried out on this species from 2003-2015. The authors provide reviews of their studies on Allium cepa, including: the morphometric analysis of root apex cells; methods of injection for the Allium-test; the blockade of onion root growth by methotrexate; the results of NMR spectroscopy for the analysis of metabolites in the meristem zone. Additionally, this compilation gathers the existing scientific evidence on the antimicrobial activity of Allium-derived compounds to establish whether it is possible that these molecules may be useful in the treatment of human infections The authors also present the results of multi-year monitoring of the occurrence of pesticide residues in onion and garlic by liquid and gas chromatography coupled with tandem mass spectrometryas well as their interpretation in terms of compliance with the maximum residue limits established by the European Union in the Directive EC/396/2005. Lastly, a comprehensive overview of tissue culture regeneration methods and their uses for the improvement of Allium species is presented and discussed.