The palmaris longus muscle is one of the most variant muscles in the human body. Its variations such as the palmaris profundus can cause nerve compression symptoms. Here, we present a case of severe nerve affection due to a palmaris profundus muscle. The palmaris profundus tendon was partially resected at intervention. Pain symptoms started immediately after wearing off of the local anesthetic, and revision surgery had to be performed. Severe traction on the median nerve by the palmaris profundus tendon could be observed at revision. The resection of the palmaris profundus tendon instantly eased the patient's severe pain. At preoperative examination and planning of surgery, the palmaris profundus was not detected. As there is no test for the detection of anatomic variations of the palmaris longus muscle at physical examination, discovering such anomalies is not possible without imaging tools. Ultrasonographic examinations aid in preoperative planning of carpal tunnel release, especially at revision surgeries.