Methods and systems for adjusting a security level of a self-checkout system based on shopper assistant intervention are disclosed. According to an aspect, a method includes deducing that shopper assistant intervention occurs in a self-checkout environment based on detection of one or more events in a self-checkout system. The events may occur at shopper terminals of the self-checkout system and may require attention of a shopper assistant monitoring the shopper terminals. The method also includes adjusting a security level of the self-checkout system in response to deducing that shopper assistant intervention occurs. Further, the method may include implementing a predetermined action in response to adjusting the security level of the self-checkout system.