Abstract High-technology companies that discover new technological opportunities face two critical decisions: whether and when to collaborate in exploiting these opportunities. Prior research has examined factors such as transaction costs that determine whether firms decide to collaborate. In this study, we aim to understand when firms collaborate in exploiting opportunities. To this end we study the history of 86 biopharmaceutical product-development projects. We find that factors that reduce articulation and appropriation uncertainties in these projects—patent protection, high R&D intensity of the discoverer, partners’ prior collaboration experience, and support infrastructures in the industry—can speed up collaboration. Interestingly, project-specific factors do not seem to affect timing.