Computational chemistry is a well-established discipline in the pharmaceutical industry and in recent years it’s been growing fast in the crop protection field too. A number of diverse molecular modelling techniques, ranging from quantum mechanics calculations to molecular dynamics simulations, can be effectively applied to many aspects of agrochemical research and contribute to the elucidation of modes of action and the design and optimization of novel active ingredients, while addressing resistance and selectivity issues. This talk will discuss, through a selection of case studies, the contribution and impact of molecular modelling in different fields of agrochemistry, aiming at the development of selective, safe and resistance-breaking products.