Horner's syndrome may be due to a variety of serious underlying disorders including cervical neuroblastoma. Horner's syndrome results from a unilateral disruption of the sympathetic innervation to the head and neck. We report a patient with cervical neuroblastoma in whom post operative metaiodobenzylguanidine (MIBG) scans showed a striking decrease in uptake in the ipsilateral salivary glands. Since the bio-distribution of I123 metaiodobenzylguanidine in the salivary glands in also dependent on sympathetic innervation, the presence of Horner's syndrome can be reflected in the MIBG scan.