PurposeHorses play an important role in the agricultural industry around the world. The equestrian sector offers new markets and sustainable business opportunities. This paper, based on a structural equation modelling approach, seeks to explore the interests of Romanian entrepreneurs in developing a sustainable business in the equestrian sector by investing in the use of horse manure. This manure is an important renewable resource in the circular economy, including in the production of bioenergy and bio-fertilizers. The present research investigates whether there is an interest in developing such a business in Romania, built around three pillars: the environment, society and the economy.Design/methodology/approachPLS-SEM is an appropriate method for this research, where prediction of interest for sustainable entrepreneurship plays a central role. In total, 153 responses have been collected and validated based on a questionnaire and the invitations to complete were sent to people who are already entrepreneurs or have intention to become entrepreneurs in the near future.FindingsThe structural model shows that society's interest has the strongest effect on developing a sustainable business model through horse manure. Surprisingly, the study does not reflect an expected correlation between the interest in the environment and the development of a sustainable business model through horse manure resulting in bioenergy.Originality/valueThis study contributes to arousing the interest in research and even the development of a business by presenting the sustainability factors in the horse industry and adopting technological innovations, services, products and business models. The study was conducted in Romania, where, currently, the manure produced by horses is underexploited, and the equestrian sector requires new business models, innovations and sustainable development.