To address challenges constraining prior research on evaluation of entrepreneurial projects, we develop the concept of Venture Idea Assessment (VIA) and validate an instrument to capture it. VIA concerns the assessment of Venture Ideas (VI) unbundled from assessment of any agents with whom they may be associated. The assessment can be performed by anybody at any stage of the venture development process, not just by potential founders at its outset. We develop and validate a parsimonious VIA measure across six empirical studies using a broad set of assessors and VIs using interviews, experiments and surveys following real-world start-up processes and decisions. In a research agenda we outline how the VIA platform—the concept and its operationalization—can be employed in novel research across various streams of entrepreneurship research.