After reviewing the different techniques assessing state-axniety, the authors emphasize the difficulties to distinguish state from trait on the sole basis of factorial content. Results obtained on different samples (mental patients, surgical patients and normal subjects)through two new anxiety self-rating scales (trait and state) are presented. On the basis of these results, the authors show the usefulness of the score indicating the discrepancy between trait and state levels. It appear that the direction (positive or negative) of the difference between trait and state levels gives a better evaluation of the actual state than the state score alone. The results imply the utilization of both self-rating scales (trait and state) in order to obtain the optimal assessment of the state.