Amyloidosis is a rare benign disease characterized by the extracellular deposition of nonsoluble fibrillar proteins (amyloids) within organs. Laryngeal amyloidosis (LA) accounts for only 9%-15% of all cases of amyloidosis. Since clinical manifestations and laryngoscopic findings often overlap with those of laryngeal cancer, it is challenging to differentiate LA from laryngeal cancer prior to surgical biopsy. We report a case of LA mimicking laryngeal cancer, in which the diagnosis was facilitated by preoperative ultrasonography (US) and US-guided core-needle biopsy (US-CNB) prior to surgical biopsy. The US findings of this case were distinguishable from those of laryngeal cancer, which enabled us to consider a diagnosis other than laryngeal cancer. Amyloidosis was diagnosed preoperatively using office-based percutaneous US-CNB, avoiding general anesthesia needed for suspension laryngoscopic examination. This case suggests that US and US-CNB could be used as supplementary diagnostic modalities to evaluate suspicious laryngeal masses mimicking laryngeal cancer.