A parotid sialocele is a salivary cavity arising at the expense of a parotid duct. It is typically post-traumatic or iatrogenic after parotid surgery [
1]. The diagnosis is eminently clinical, using the physical examination and clinical history [
2]. Fine-needle aspiration confirms the diagnosis with a high level of amylase originating from the saliva. An imaging study, including high resolution ultrasonography, is considered helpful for identifying ductal injury, size, location of the cyst, and fistula formation. Sialography is also considered a mainstay for diagnosis and evaluation but may increase the pressure in the sialocele, causing rupture and fistula [
3]. Management for sialocele is diverse from conservative treatment to radical surgical modalities, and factors to be considered are time elapsed since injury, gland site affected, trauma mechanism, and experience of the surgeon [
4]. However, conservative management is usually given initially unless obvious ductal injury is suspected that necessitates surgical repair. The first-line methods include successive percutaneous aspirations, compress application, and parenteral nutrition to reduce autonomous salivary stimulation. Antisialogogue medications including anticholinergic agents are also administered to inhibit the action of acetylcholine at the postganglionic nerve endings of the parasympathetic nervous system. However, side effects can included xerostomy, constipation, photophobia, tachycardia, and urinary retention [
5]. When conventional conservative management fails, BTX is considered. BTX blocks acetylcholine release, thereby inhibiting neurotransmission at the secremotor parasympathetic autonomic nerve ending responsible for salivation [
6]. Marchese Ragona et al. [
7] and Vargas et al. [
8] have also reported the use of BTX in treating parotid sialocele resistant to conventional modes of treatment. They have asserted that BTX is highly effective and non-invasive for this condition. However, considering the complicated anatomy of the parotid region, consisting of facial nerves and vessels, blind injection of BTX can be hazardous and burdensome, especially for unexperienced physicians. Real-time ultrasonographic assistance can be utilized to evaluate the exact location and depth of the injection to stay within the superficial parotid gland in order to avoid post-injection facial nerve paralysis or vessel damage. Our patient also showed no sign of facial nerve damage. Dessy et al.[
9] reported BTX injection for treating parotid fistula after face-lift surgery. Considering the 18,938 face-lift procedures performed in South Korea in 2014, the incidence of sialocele or sialo-cutaneous fistula could be considerable, and physicians should be able to utilize effective methods of botulinum injection when confronting resistant sialocele cases. Numerous studies have reported the use of BTX injection for sialo-cutaneous fistula and sialocele, but a consensus on the exact location, amount, and approach site to prevent facial nerve damage has not been established because of the complexity of the parotid anatomy. To the best of our knowledge, we herein present the first case of ultrasonographically guided injection of BTX for sialocele treatment. We were able to guarantee an easier and safer approach to the parotid gland by use the imaging guidance. For sialocele cases resistant to conventional modes of treatment, BTX A injection can be a valuable option and ultrasonographic guidance enables more precisely locating the gland and safer injection without complications.