"While business accelerators remain understudied in the academic literature, there is growing interest in understanding how accelerators work and where they provide value to entrepreneurs. In this paper, we focus exactly on this question – we examine how mentorship and investor ties, two key aspects observed across accelerators in general lead to positive accelerator outcomes and through them, to longterm firm success outcomes for the start-ups participating in accelerators. Using the full cohort (n=105) of an international accelerator, we follow the progress of the startups during the accelerated period and continue to follow these startups for 15 months. We find that startups that participate more in mentorship events have higher likelihood of achieving short-term outcomes during the accelerator, such as the release of a prototype and generating revenue for the first time. Similarly, startups that develop more investor ties during the accelerator survive and raise capital at a higher rate. Finally, we find evidence that certain short-term accelerator outcomes also increase the chances of survival and investment. On the basis of these results, we provide practical implications for start-ups as well as managers of accelerator programs, in addition to theoretical contributions to entrepreneurship research."