To investigate the reliability of the soil parameters predicted by flat dilatometer test, several documented data have been reviewed from sites in Europe and Southeast Asia as well as published data from Japan. The results of this review have shown that the equations proposed by Marchetti provide reasonable estimates of the in-situ undrained shear strength. However, some discrepancies were observed between laboratory results and DMT results about overconsolidation ratio and coefficient of earth pressure at rest. To this end, modified equations estimating the both soil parameters are proposed. In addition, a new correlation has been proposed to estimate N-values from flat dilatometer test.