New venture ideation is a crucial early phase of entrepreneurship where entrepreneurs identify unmet needs and devise creative solutions. In this process, entrepreneurs generate many ideas before selecting one they deem worthy of pursuing. Despite the benefits of generating numerous ideas, the cognitive factors that support ideation are typically considered innate and not easily developed in the short-term, raising questions about how entrepreneurs can enhance their creative capacity to generate new venture ideas. Mindfulness, characterized by receptive attention and awareness of the present, has been shown to influence cognition in a manner conducive to creativity, suggesting its utility for new venture ideation. Building upon research at the intersection of mindfulness and creative cognition, we theorize that mindfulness promotes idea generation and that differences in mindfulness practice and entrepreneurial self-efficacy jointly shape this effect. We test our theorizing across two studies. Study 1 establishes a significant relationship between trait mindfulness and idea generation while Study 2 utilizes an experimental design to demonstrate the causal effect of mindfulness meditation on new venture idea generation. Our results advance entrepreneurship and mindfulness research by highlighting mindfulness as a valuable tool for new venture ideation and identifying contingencies that affect this relationship.