In this paper the psychic world of a woman who is diagnosed as fibromyalgia syndrome is evaluated with the clinical material and the contribution of projective tests of Rorschach and TAT, in terms of the essential depression and operative thinking. The responses concerning the essential depression or the traces of them are interpreted according to the psychoanalytic psychosomatic theory. Deficiency in the primary idendification with the mother pioneer to fragility in the psychic economy, thereby sets the basis for operative thinking and essential depression. The operative thinking without the presence of fantasmatic productivity and richness may be an encounter against essential depression. The contribution of projective tests with all dimensions in clinical treatment will be a facilitating and enrichment factor in diagnosing the corporal illness as well as will serve for a better understanding of the psychic organisation.