Background Transient elastography (TE) is a non-invasive method that allows liver fibrosis staging on the basis of hepatic stiffness measurements. Little is known about the influence of chronic liver inflammation on the stiffness of hepatic tissue. Methods A total of 112 patients with chronic hepatitis C underwent a liver biopsy and TE. Results Mean values of liver stiffness (in kPa) by inflammation strata were 4.8, 6.4, 9.4 and 12.6 for A0, A1, A2 and A3, respectively, in hepatitis C virus (HCV)-monoinfected individuals ( P=0.018). These figures were 8.0, 10.4, 12.9 and 12.6 for A0, A1, A2 and A3, respectively, in HIV– HCV-coinfected patients ( P=0.35). In HCV-monoinfected patients with fibrosis staging F3-F4, mean liver stiffness was greater if inflammation was ≥A2 versus A0-A1 (14.6 versus 6.2 kPa; P=0.04). By contrast, no differences in liver stiffness according to inflammation were seen in HCV-monoinfected patients with <F3 or in HIV-HCV-coinfected patients regardless of liver fibrosis staging. Among HCV-monoinfected patients, mean liver stiffness was greater for alanine aminotransferase >100 versus <100 IU/l (10.5 versus 8.5 kPa; P=0.04). Conclusions The extent of liver inflammation might affect the accuracy of TE for staging liver fibrosis, particularly in HCV-monoinfected patients with advanced fibrosis on liver biopsy and/or increased alanine aminotransferase levels.