BACKGROUND: Contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) can visualize necrotic areas and vessels inside lesions. CH-EUS findings combined with EUS-guided fine-needle aspiration (EUS-FNA) improves diagnosis in pancreatic solid masses. CH-EUS can also guide EUS-FNA (CH-EUS-FNA), potentially improving the diagnostic rate of EUS-FNA, but such superiority has not been proved in prospective studies. We aimed to assess whether CH-EUS-FNA is superior to standard EUS-FNA for specific diagnosis of solid pancreatic masses and what factors affect the diagnostic rate. METHODS: This randomized controlled study in one tertiary medical academic center included patients with suspected pancreatic solid masses on transabdominal ultrasound or computed tomography (CT) scan. Two passes with a 22-G standard FNA needle were done using EUS-FNA and CH-EUS-FNA in random order, and the visible core obtained was sent for histological analysis. Final diagnosis was based on EUS-FNA or surgical specimen results and on 12-month follow-up by imaging. RESULTS: 148 patients were evaluated. EUS-FNA and CH-EUS-FNA showed diagnostic sensitivities of 85.5 % and 87.6 %, respectively (not significantly different) and the combined sensitivity of the two passes was 93.8 %. The false-negative rate was not significantly different when hypoenhanced or hyperenhanced lesions were compared with the EUS-FNA results. No differences were seen for the results related to location, size, tumor stage, chronic pancreatitis features, or presence of biliary plastic stent. CONCLUSIONS: The diagnostic rates for samples obtained using 22-G needles with standard EUS-FNA and CH-EUS-FNA were not statistically significantly different.