BACKGROUND: Acoustic Radiation Force Impulse Elastography is a new method for non-invasive evaluation of liver fibrosis. AIM: To evaluate the impact of elevated alanine aminotransferase levels on liver stiffness assessment by Acoustic Radiation Force Impulse Elastography. METHODS: A multicentre retrospective study including 1242 patients with chronic liver disease, who underwent liver biopsy and Acoustic Radiation Force Impulse. Transient Elastography was also performed in 512 patients. RESULTS: The best Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis was 1.29m/s in cases with normal alanine aminotransferase levels and 1.44m/s in patients with alanine aminotransferase levels>5× the upper limit of normal. The best cut-off for predicting liver cirrhosis were 1.59 and 1.75m/s, respectively. Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis and cirrhosis were relatively similar in patients with normal alanine aminotransferase and in those with alanine aminotransferase levels between 1.1 and 5× the upper limit of normal: 1.29m/s vs. 1.36m/s and 1.59m/s vs. 1.57m/s, respectively. For predicting cirrhosis, the Transient Elastography cut-offs were significantly higher in patients with alanine aminotransferase levels between 1.1 and 5× the upper limit of normal compared to those with normal alanine aminotransferase: 12.3kPa vs. 9.1kPa. CONCLUSION: Liver stiffness values assessed by Acoustic Radiation Force Impulse and Transient Elastography are influenced by high aminotransferase levels. Transient Elastography was also influenced by moderately elevated aminotransferase levels.