Various embodiments of the present invention generally relate to systems and methods for identifying suspicious orders for controlled substances based on performing checks on a received order using historical information on previous orders. According to various embodiments, these checks may include: (1) comparing the order quantity for the received order with the order quantity history for the customer who placed the order for the controlled substance; (2) comparing the order quantity and the days since the last order was shipped to the customer for the same controlled substance with the order quantity history and the days between orders for the particular customer and controlled substance; (3) comparing the order quantity with order quantity history for orders received by customers of the same type for the controlled substance; and (4) comparing the order quantity with order quantity history for any customer for the particular controlled substance.