PURPOSE: To evaluate the clinical usefulness of US-guided automated gun biopsy of neck masses. MATERIALS & METHODS: US-guided biopsy was performed using 20 gauge or 18 gauge biopsy gun to 31 patients in whom masses were detected by neck US. Authors divided the obstained core tissues into diagnostic or non-diagnostic tissue on a basis of histopathologic diagnosis. We also analysed the site, size,& internal echo of the masses. RESULTS: In 27 out of 31 masses(87.1%), specimens were obtaained adequately for histopathologic diagnosis. There were 17 cases (85.0%) of thyroid gland, 7(87.5%) of lymph node, 2(100%) of parotid gland, and 1(100%) of buccal space. The percutaneous biopsy results were all agreed in 24 masses of whick final diagnosis was made through operation(n=5), surgical incision biopsy(n=1), percutaneous biopsy of metastatic hepatic mass(n=1), clinical symptom and follow up US over 6 months(n=17). After gun biopsy there wasn't any other compications except some discomfort and pain in 23 patients(74%). CONCLUSION: US-guided percutaneous automated gun biopsy in neck mass is a useful procedure for therapeutic plan as we can obtain enough specimens for histopathologic diagnosis and safely operate in short time.