Oblique lateral interbody fusion (OLIF) has recently gained widespread use as a minimally invasive surgical procedure for degenerative lumbar disease. OLIF has several advantages but can also lead to several possible complications. For example, although less common, access through the retroperitoneal cavity can cause ureteral injury. Here, we report two cases of ureteral complications that occurred during consecutive OLIF procedures. One involved a 77-year-old female patient who had a double-J catheter inserted due to ureteral injury during surgery, and the other involved a 69-year-old male patient suspected of having a ureteral stricture due to retractor compression. To prevent ureteral complications in OLIF, it is necessary to accurately identify the anatomy of the ureter through preoperative imaging and to pay special attention during surgery.