Purpose This study aims to identify how the personal social capital of opinion leaders contributes to the market adoption of start-up innovations. Design/methodology/approach A design-oriented case study is undertaken with a start-up company focusing on the development and commercialization of innovations in the veterinary market. Based on a literature review, the authors examine the social capital in value creation and the role of opinion leaders and use qualitative methodology and semi-structured in-depth interviews to collect data. Findings The adoption of innovations could start with opinion leaders that will later share their experience with other members of the professional community. In turn, social capital allows for creating a collaboration between start-ups and leaders based on a number of specific parameters. Originality/value This paper contributes to marketing literature by providing new insights regarding collaboration between start-ups and opinion leaders. The collaboration between opinion leaders and start-ups could be implemented not only in the veterinary industry but also in other industries with minor adaptations. Authors demonstrate how the social capital of external stakeholders may be used as a resource of the company for business development. The main contribution of this study is to demonstrate that social capital could be used as a parameter for the adoption of innovations. The key parameters that allow creating cooperation between start-up and opinion leader have been identified.