Environmental assessments in pesticide product development are generally restricted to plant uptake and emissions of active ingredients. Life-cycle assessment (LCA) enables a more comprehensive evaluation by additionally assessing the impacts of pesticide production and application (e.g. tractor operations). The use of LCA in the product development of pesticides, in addition to the methods commonly applied, is therefore advisable. In this paper a procedure for conducting LCA in early phases of product development is proposed. In a case study, two plant-growth regulators from different product generations were compared regarding their application in intensive production of winter wheat. The results showed thatthe reduced emissions from active ingredients of the newer pesticide were compensated by higher impacts from the production process. The authors draw the conclusion that it is important to consider environmental objectives in the procurement of precursors, in addition to the classical goals of increasing the efficacy and reducing the nontarget effects of pesticides. Moreover, the case study showed that decisions based on uncertain results in early stages of product development may need to be revised in later stages, e.g. based on investigations of pesticides' effects on crop yield.