Index‐insured loans offer considerable advantages over standalone insurance policies for improving farmers’ access to agricultural credit. However, research on demand for such products and their impact on profitable investment decisions has been limited and conflicting. In this article, we investigate the impact of index insurance on demand for credit and investment decisions using a lab‐in‐the‐field experiment conducted in rural Tanzania. We find that index insurance increases demand for credit and high‐risk high‐return investments.