Business accelerators provide entrepreneurs with a combination of capital and specific support resources to help them grow rapidly and scale their business idea. Despite their rapid emergence as key role players in the entrepreneurial ecosystem, research is still scant about their impact in new ventures development. This paper examines the effects of business accelerators based on the achievement of positive results from the dynamic capabilities perspective. Specifically, a qualitative and descriptive approach of Y Combinator’s business accelerator methodology has been applied. The analysis shows how Y Combinator contributes to the generation of dynamic capabilities in companies through the implementation of specific actions and resources embedded in its business acceleration program. Findings reveal that business accelerator stimulates dynamic capabilities of portfolio firms. It can help them to gain competitive advantage and superior performance in the market compared to companies that do not participate in an acceleration program.