Background: Assessment of anterior tibial displacement is the crucial part of clinical examination of the knee joint. The purpose of this study was to investigate repeatability of GNRB knee arthrometer. Methods: Measurements of knee anterior laxity were repeated seven times on one subject with 20 minutes between each repetition. Knee arthrometer GNRB was removed from the subject’s knee after each measurement. Knee anterior laxity was measured at force 134N and 250N on the right and left knee, respectively. Data was analysed with descriptive statistics. Standard error of measurement (SEM) was calculated in order to define the stability of repeated measurements. Results: Average knee anterior laxity is 7 mm at force 134N, while at force 250N, average knee anterior laxity is 9.9 mm. Standard error of measurement was ranging from 0.152 to 0.189 mm at both forces 134N and 250N, respectively. Conclusions: Repeatability of knee anterior laxity measured with GNRB knee arthrometer is clinically acceptable, since the SEM was lower than 0.2 mm.