This paper investigates how entrepreneurs frame the sustainability of their ventures when pitching their business ideas to investors. With this study, we aim to contribute to the stream of entrepreneurship literature focusing on sustainable entrepreneurship development among purpose-driven startups. Through the application of framing theory, we explore and categorize sustainability-oriented frames applied in business pitches. We apply a qualitative methodology and an abductive approach in collecting and analyzing data from startup pitches presented at the startup event Slush held in Finland in 2017 and 2018. The findings indicate how frame blending is gradually transitioning to frame shifting as startup entrepreneurs are increasingly referring to sustainability aspects as additional elements in the conventional profit-driven business pitching model. Thus, the Need-Approach-Benefit-Competition model is converted into more sustainable business contexts with emerging sustainability frames related to sustainability themes on three different levels, the micro, meso and macro levels with cognitive, strategic, technological and institutional frames.