Various adjunct releasing mechanisms are provided herein that can be incorporated into surgical devices, such as an end effector of a surgical stapler. For example, an adjunct releasing mechanism can act to release an adjunct attached to an end effector of a surgical stapler upon deployment of staples retained within the end effector. The adjunct can be retained on the end effector through a variety of means, such as through use of adhesive or by having a portion of the adjunct partially received within cavities formed on a tissue-facing surface of the end effector. The releasing mechanisms can extend into the cavities formed on the tissue-facing surface of the end effector to cause the adjunct to detach from the end effector upon deployment of staples.