Literature from the business and design disciplines describes two important subprocesses of the entrepreneurial journey: new venture creation and new product development. This study uses evidence from qualitative research with Designer-entrepreneurs (D-entrepreneurs) to describe a third important subprocess, which we refer to as the Designer’s Mindset Transition (DMT), which can either hinder or propel the other subprocesses. Thirty-seven participants, including eleven D-entrepreneurs in product-based start-ups, participated in the study. Four designer-entrepreneurs’ mindsets were identified within the DMT subprocess: The Artisan, the Configurator, the Opportunity Seeker, and the Design Leader. They followed a progression that moves the Designer-entrepreneur from the effectual logic (means-oriented) towards a causal logic (goal-oriented). Evidence from the study demonstrates that designers starting from the Artisan mindset were not always driven by their purported user-centric approach. Instead, key drivers were their priorities, interests, and beliefs, established at the outset of the venture.