Several variants of Guillain–Barré syndrome have been described. The Fisher syndrome (FS) presents with ataxia, areflexia, and ophthalmoparesis. The pharyngeal–cervical–brachial (PCB) variant presents with bulbar weakness, along with arm and neck weakness. The 2 variant syndromes can overlap. Both the isolated and overlap syndromes respond to immunomodulatory treatment, thus are important to recognize clinically. Ganglioside antibodies are detectable in the variant syndromes and may aid in their diagnosis. The FS typically is associated with anti-GQ1b antibodies, and PCB is typically associated with anti-GT1a antibodies, whereas the overlap syndrome may have both ganglioside antibody subtypes. We present a case of overlap FS–PCB syndrome with a novel ganglioside antibody profile of GM1 and GD1b antibodies, which typically are associated with other variant syndromes. This case suggests the need for all ganglioside antibodies to be tested in suspected variant Guillain–Barré syndromes. The antibodies may prove especially useful in cases in which the clinical diagnosis is ambiguous.