A tissue retrieval device includes an introducer tube and a tissue retrieval bag. The introducer tube is insertable into a patient through a trocar. The bag may be selectively exposed at the distal end of the introducer tube, receive a tissue specimen, and be withdrawn from the patient. The bag includes a plurality of folds allowing the bag to transition from a folded configuration to an unfolded configuration. The folds may extend along a length of the bag transverse to the introducer tube; or along a length of the bag parallel to the introducer tube. The folds may extend about a perimeter of the bag, such as a circumference of the bag, and may be spaced apart along a length of the bag transverse to the introducer tube. The folds may be formed by petals that provide the bag with a generally spherical configuration when the bag is unfolded.