Onions ('Allium cepae L.') are an important field vegetable in Ontario with a farm gate value exceeding $21 million in 2004. Onion smut (OS) ('Urocystis cepulae' Frost) and onion maggot (OM) (' Delia antiqua' Meigen) are the most economically important pests of onions in Ontario. Without effective control measures, stand loss from each pest is more than 50%. Several novel reduced-risk fungicides and insecticides seed treatments have shown potential for OS and OM control. These chemicals can be used at a very low rate. The overall objective of this project was to develop an efficacious integrated approach to OS and OM control using insecticide/fungicide seed treatment combinations. Results over 2 years showed that using insecticide/fungicide seed treatments provided comparable control of OM and OS to the industry standards and represent ca. 99% reduction in pesticide use. Onion growers will benefit from this research, through the development of IPM programs for OS and OM controls.