Based on the results of a multiple case study of seven manufacturing firms, a contingency framework for harnessing fuzziness in the front end of innovation is proposed by delineating two discrete capability paths through which new product ideas are developed into corroborated product definitions. The study illustrates that ideas characterized by high levels of fuzziness benefit from following an exploratory path, where the creative potential of fuzziness is embraced by deploying problem-formulation and problem-solving capabilities. In contrast, ideas at low levels of fuzziness benefit from following an exploitative path, where fuzziness is tolerated by drawing upon idea-refinement and process-management capabilities. When the fuzziness level of the idea and the set of capabilities to develop the idea are poorly aligned, the idea-development process is either inefficient or runs the risk of stalling. These findings have theoretical and practical implications for the front end of innovation and new product idea development. © 2021 The Authors. Published by Elsevier Ltd.