Background & Aims: Liver stiffness (LS) measurement by Transient Elastography (TE) has been widely accepted as a tool for fibrosis assessment. The aim of this study was to assess LS dynamics in a group of patients with HCV liver cirrhosis after interferon free treatment (IFT).Methods: This two-center clinical trial included 225 patients with compensated HCV cirrhosis (all genotype 1b), who received IFT for 12 weeks. All patients were evaluated by means of TE at the beginning and at the end of treatment (EOT), and a subgroup (170 patients) also 12 weeks after EOT; all of them had sustained viral response (SVR). Reliable LS measurements (LSM) were defined as a median value of 10 valid LSM, with IQR <30% and SR ≥60%. Both M and XL probes were used. For diagnosing cirrhosis we used a cut-off value of 12kPa as proposed by the Tsochatzis meta-analysis. We considered a decrease or increase of more than 10% in LSM as being significant.Results: Out of 225 subjects, reliable measurements were obtained in 93.7%, so that the final analysis included 211 patients. The mean LS values decreased significantly after IFT: 26.4±11.7 vs. 23.5±13.3 kPa (p=0.01). Most patients, 59.2% (125/211) presented more than 10% decrease in LS values, 24.1% (51/211) had stable LS values, while in 16.4% (35/211) cases, the LS values increased. In the subgroup of 170 patients with LSM also performed 12 weeks after EOT (SVR), the mean LS values were significantly lower as compared to baseline: 21.3±11 kPa vs. 27.4±11.9 kPa (p<0.0001) and also as compared to EOT: 21.3±11 kPa vs. 23.7±13.3 kPa (p<0.0001).Conclusion: In our patients with HCV liver cirrhosis, the mean LS values evaluated by TE significantly decreased after antiviral treatment at EOT and also 12 weeks after EOT as compared to baseline. Overall, about 60% of patients had LS values at EOT lower than at baseline, while 12 weeks after EOT about 75% of patients had LS values lower than at baseline. –.Abbreviations: APRI: aspartate aminotransferase platelet ratio index; BMI: body mass index; DAA: direct acting agents; EOT: end of treatment; FIB-4: fibrosis 4; HBV: hepatitis B virus; HCV: hepatitis C virus; IFT: interferon free treatment; IQR: interquartile range; LS: liver stiffness; LSM: liver stiffness measurements; SR: success rate; SVR: sustained viral response; TE: Transient Elastography.