A surgical stapling device including a self-righting anvil assembly includes an anvil center rod and a pivotable anvil head. The surgical stapling device includes an anvil retainer assembly having a locking member. A cam member is provided to retain the locking member in a locked position and, thus, the anvil head in the operative position until after firing. In another embodiment, a tiltable anvil assembly includes a center rod and a head assembly pivotally secured to the center rod. The head assembly includes a housing, a post, an anvil plate and a backup member. The backup member is movably positioned from a first to a second position. A retainer member is positioned between the backup member and the housing. In another embodiment, a passive lockout mechanism is operably associated with a trigger lock on the handle assembly of the surgical stapling device.