<p>Biopesticides, pesticides based on living organisms and/or their bioactive compounds, are increasingly being used as alternatives and replacements to chemical and synthetic pesticides. This is largely due to human and environmental safety concerns, the emergence of pest resistance (collectively insect pests, weeds and diseases), and the move towards holistic pest and disease control approaches. While the number and diversity of agents used in biopesticides slowly increases, the approach to developing these products remains largely ad hoc, resulting in less than 10% success rate for development projects. Here we review the major characteristics of successful biopesticides. Our treatise focuses on the benefits of considering the entire development pathway and requirements of the intended product application before embarking on the costly process of biopesticide development and commercialisation. By a priori consideration of the characteristics of both the target pest and market, and the potential limitations of the candidate microorganism and/or its bioactives (e.g. environmental persistence, ease and cost of mass production), the development pipeline can be streamlined and targeted on projects with the greatest likelihood of success. We provide a detailed consideration of the key factors that underpin successful (or not) biopesticide development and provide decision trees to support the a priori process.</p>