Benefit Corporations and B Corps represent alternative models of enterprise, often referred to as “hybrid companies” that bridge the for-profit and not-for-profit models. Italy is the first country outside the USA to pass Benefit Corporation legislation and introduce the Società Benefit. A large number of Italian Benefit Corporations are small- and medium-sized companies (SMEs), since SMEs are widespread within the entrepreneurial fabric and have great relevance in the Italian socio-economic context. A key issue in the emerging debate on small- and medium-sized Benefit Corporations concerns how these companies—with limited reach and considerable financial and human resource constraints—can effectively absorb their added social responsibility. In particular, such firms need to manage their dual mission, integrate social and environmental goals in their business model, and incorporate accountability mechanisms, all while scaling up and garnering the necessary resources to be economically competitive. Starting from these premises, this paper focuses on the performance measurement and reporting systems that are adopted by SMEs that are also Benefit Corporations, and investigates whether benefit impact assessment indicators integrate into an overall sustainability performance management system. To achieve this goal, an exploratory case-based analysis on seven small- and medium-sized Italian-certified Benefit Corporations is presented.