The procalcitonin assay is a popular tool among antimicrobial stewardship programs. There are procalcitonin algorithms and further guidance in the medical literature to aid clinicians in decision making regarding antibiotic therapy initiation and duration. Diagnostic utility of procalcitonin levels is a matter of debate and should be interpreted only in conjunction with the context of the patient's clinical picture. Researchers present a case of ambiguous procalcitonin findings along with a stepwise approach in reviewing the medical literature. Although not listed as a common cause of false-positive procalcitonin results, it was felt that advanced non–Hodgkin lymphoma coupled with worsening renal function was ultimately the cause of this patient's elevated procalcitonin levels.