This study explores value co-creation in university industry collaborations. The study is inspired by the constructivist approach to grounded theory and self-ethnography and based on interviews with 27 informants (eleven industry mentors and 16 academics) engaged in university industry collaborations. The findings suggest that co-creation depends on knowledge readiness and knowledge readiness develops through an interplay between temporary geographical and cognitive proximity. This study contributes to the existing literature on value co-creation, university industry collaborations, and proximity as follows: first, we shed light on the use of the co-creation perspective to enhance understandings of how value can be co-created in university industry collaborations. Second, we introduce the concept of knowledge readiness and demonstrate that co-creation in university industry collaborations between academics and industry mentors rests on knowledge readiness. Knowledge readiness concerns knowledge use and develops in the interplay between temporary geographical and cognitive proximity. We describe knowledge readiness as a subdimension of cognitive proximity. Knowledge readiness takes time to develop and is important for value co-creation and, subsequently, innovation in university industry collaborations.