We argue that the recent large increase in deposits’ turnover in many developing countries with high HIV/AIDS prevalence is associated with the spread of the disease. The point is that the need to pay for individual treatments force large‐scale withdrawals of households’ deposits, and that those large withdrawals put the banking industry at risk. In a standard demand‐deposit model where the HIV/AIDS prevalence among depositors is random, we show that (1) the probability of a large‐scale banking failure without a bank run increases as the odds of any prevalence level increases, and (2) it is always optimal to deposit, and thus to accept the risk of banking failure, to maintain long‐term investments in place.