Primary intra- or transabdominal transplantation of an extended rectus abdominis myocutaneous (ERAM) flap may help prevent surgical complications of pelvic resections. Surgical delay of the ERAM flap may help prevent intra-abdominal (partial) flap loss after transplantation in highly complex situations including previous irradiation. We report on the outcome of this approach and the risk-factors associated with an eventful outcome. From 2012 to 2020, 105 delayed ERAM flaps were consecutively applied immediately following extended pelvic resections after chemoradiation or hyperthermic intraperitoneal chemotherapy. We addressed the increased reconstructive demands by designing the flap in line with the 10th rib and delaying the flap's skin island. All post-operative complications were assessed in light of patient-related or procedure-related potential risk-factors. Major complications occurred in 39 patients. These were correlated with surgery for residual or recurrent malignancy (p < 0.01), with tip necrosis after flap delay (p = 0.02), and with the use of a mesh to close the abdominal donor site (p < 0.01). (Partial) flap loss occurred in 4 cases. We observed a comparably high rate of major complications after ERAM transplantations for increasingly extending indications of perineal-pelvic resections. We consider this to be attributable to poorer patients' conditions and disease processes, rather than to flap viability. Delay of the flap allowed for the use of large and voluminous flaps with comparably little (partial) flap loss.