A tissue specimen retrieval device, comprising: a housing; an outer shaft extending distally from the housing and defining a longitudinal axis; an end effector assembly extending distally from the outer shaft in a deployed position of the end effector assembly; an actuator operably associated with the housing; and an articulation mechanism operably coupled between the actuator and the end effector assembly, the articulation mechanism including: an articulation block supporting the end effector assembly thereon, the articulation block rotatable between a first orientation and a second orientation to thereby articulate the end effector assembly between an aligned position and an articulated position; a spring operably associated with the articulation block and configured to bias the articulation block towards the second orientation; and an actuation sleeve slidable relative to the articulation block, in response to actuation of the actuator, from an engaged position, wherein the actuation sleeve is disposed about the articulation block to thereby retain the articulation block in the first orientation, to a disengaged position, wherein the actuation sleeve is positioned proximally of the articulation block such that the articulation block rotates to the second orientation under the bias of the spring to thereby articulate the end effector assembly from the aligned position to the articulated position, characterised in that the end effector assembly is deployable relative to the outer shaft from a retracted position, wherein the end effector assembly is disposed within the outer shaft, to the deployed position, the tissue specimen retrieval device further comprising another actuator operably associated with the housing and configured to selectively deploy the end effector assembly from the retracted position to the extended position. a housing; an outer shaft extending distally from the housing and defining a longitudinal axis; an end effector assembly extending distally from the outer shaft in a deployed position of the end effector assembly; an actuator operably associated with the housing; and an articulation mechanism operably coupled between the actuator and the end effector assembly, the articulation mechanism including: an articulation block supporting the end effector assembly thereon, the articulation block rotatable between a first orientation and a second orientation to thereby articulate the end effector assembly between an aligned position and an articulated position; a spring operably associated with the articulation block and configured to bias the articulation block towards the second orientation; and an actuation sleeve slidable relative to the articulation block, in response to actuation of the actuator, from an engaged position, wherein the actuation sleeve is disposed about the articulation block to thereby retain the articulation block in the first orientation, to a disengaged position, wherein the actuation sleeve is positioned proximally of the articulation block such that the articulation block rotates to the second orientation under the bias of the spring to thereby articulate the end effector assembly from the aligned position to the articulated position, characterised in that the end effector assembly is deployable relative to the outer shaft from a retracted position, wherein the end effector assembly is disposed within the outer shaft, to the deployed position, the tissue specimen retrieval device further comprising another actuator operably associated with the housing and configured to selectively deploy the end effector assembly from the retracted position to the extended position. an articulation block supporting the end effector assembly thereon, the articulation block rotatable between a first orientation and a second orientation to thereby articulate the end effector assembly between an aligned position and an articulated position; a spring operably associated with the articulation block and configured to bias the articulation block towards the second orientation; and an actuation sleeve slidable relative to the articulation block, in response to actuation of the actuator, from an engaged position, wherein the actuation sleeve is disposed about the articulation block to thereby retain the articulation block in the first orientation, to a disengaged position, wherein the actuation sleeve is positioned proximally of the articulation block such that the articulation block rotates to the second orientation under the bias of the spring to thereby articulate the end effector assembly from the aligned position to the articulated position,