Objective: To assess the inter-and intra-observer variability of acoustic radiation force impulse (ARFI) quantification in liver segments with influence of age, body mass index (BMI) and liver capsule-to-box (CB) distance. Methods: 10 healthy volunteers were examined twice, by three experienced operators, separated by a 1-week interval. 10 readings were obtained, from segments 3, 5/6 and 7/8. Age, BMI and the CB distance were noted. The Cronbach a statistic for analysis of reliability was performed for the inter-and intra-observer studies. Multivariate linear regression models determined significance of the other parameters. . For both the inter-and intra-observer study, the Cronbach a statistic was $0.7 (reliable) when taken from segments 5/6 and 7/8 but ,0.7 (unreliable) for segment 3. BMI and age showed significant (p,0.0001) but contrasting correlation (segment 5/6: BMI r50.02, age r520.02; segment 7/8: BMI r520.01, age r50.01) with ARFI velocities when analysed for the segments deemed reliable. A weak negative correlation between ARFI velocities and liver CB distance was demonstrated for both assessed segments (segment 5/6, r520.08; segment 7/8, r520.06; p,0.001). Conclusion: With trained operators, ARFI is a reliable and reproducible method of liver stiffness quantification in segments 5/6 and 7/8 but acquisition of measurements from segment 3 should be avoided. Values obtained deeper to the liver capsule allow more reliable liver stiffness quantification.