Extant literature recognizes the important role of learning in the entrepreneurial process. However, few studies have explored how learning takes place in a mutual interaction with new venture ideas (NVI). This paper aims to build theoretical understanding about the interplays between the development of NVIs and entrepreneurs’ learning. In our inductive multiple-case study with six entrepreneurs in Norway, we find that NVIs trigger the learning of entrepreneurs at several occasions and, by transforming experiences into knowledge, entrepreneurs further develop the NVIs. This paper emphasizes the mechanisms of this co-development process.