Analyses of average daily gain (ADG) and viral load (VL) suggest that selection for increased feed efficiency based on residual feed intake (RFI) does not increase the impact of Porcine Reproductive and Respiratory Syndrome (PRRS) infection on these two traits. In fact, the results show that growth of the more efficient pigs was less affected by PRRS infection than that of the inefficient line. These findings provide commercial farmers with additional incentives to invest in feed-efficient pigs.