We adapted in French the Frenchay Dysarthria Assessment (FDA) developed by P. Enderby in 1983. This tool quantitatively evaluates the organs involved in speech and provides a measurement of intelligibility. Productions of normal subjects were analyzed. Reproductibility of data (correlation and interobserver concordance) was high in 18 dysarthric patients. A study performed in 100 dysarthric patients corresponding to 4 types of dysarthria (spastic, ataxic, hypokinetic and mixte) showed that dysarthria resulted from a global impairment of organs implied in speech, rather than one specific organ. The reduction in the intelligibility score was related to organ impairment.