Overt bladder distension can compress the iliac vessels and result in lower extremity swelling mimicking deep venous thrombosis (DVT). This phenomenon has been reported in patients with bladder outlet obstruction due to prostatism but no report has been made in relation to poststroke urinary retention (UR). The authors experienced a rare case of abrupt leg edema with DVT-like symptoms due to iliac vein compression by an overdistended bladder that had developed after cerebrovascular stroke. A 74-year-old woman with left striatocapsular infarction and situs inversus presented with severe right leg swelling. Imaging studies revealed external compression of the right iliac veins by an overdistended bladder and underlying May-Thurner syndrome (MTS). The presence of situs inversus totalis resulted in the rare clinical finding of a right-sided MTS. The patient's symptoms were largely attributable to external compression of right iliac veins by bladder distension and they resolved completely after prompt bladder drainage. Follow-up imaging findings showed complete regression of right external iliac vein stenosis. This case provides the first description of lower extremity swelling manifest as an unusual complication from UR in a stroke patient. Proper and strict bladder screening with appropriate management should be implemented as important therapeutic components during the rehabilitative management of stroke patients.