This paper studies whether experienced entrepreneurs, executives, and investors can predict the subsequent outcomes of early-stage ventures by reading succinct summaries of their business ideas. We collect and examine data on 652 ventures. In research-and-development intensive sectors, the ideas that elicit more positive evaluations at early stages are significantly more likely to reach commercialization or to raise substantial funding; this pattern does not hold for ventures in non-R&D-intensive sectors. Our results suggest that, in R&D-intensive sectors, the initial business idea plays a central role in determining entrepreneurial success.