Almost half a decade ago, this journal introduced a new art therapy assessment, the Diagnostic Drawing Series (DDS) (Johnson, 1988). This instrument was created because of the clinical imprecision of existing art therapy assessment procedures and the absence of a research foundation on which to base clinical judgments (Cohen, Hammer, & Singer, 1988). Since that time, development of the DDS has continued, with updates being shared through limited circulation newsletters or professional presentations. The Diagnostic Drawing Series, designed by art therapists, is an art interview in which collection and picture analysis is linked to DSM-III and DSM-III-R diagnoses (APA, 1980, 1987). The protocol for the three-drawing assessment tool incorporates instructions for unstructured, structured and semi-structured drawing tasks (Benjamin, Hopkins, & Nation, 1987; Cohen, 1990; Turkington, 1985; Wade & Tavris, 1987). Presented with three pieces of 18 by 24 inch white paper and a 12-color box of square, soft chalk pastels, the client is asked initially to “Make a picture using these materials. ” The instruction for the second piece of paper is “Draw a picture of a tree. ” The third request is “Make a picture of how you are feeling, using lines, shapes, and colors” (Cohen, 1985). This article will review numerous reliability and validity tests of the DDS. In so doing, it will have the effect of doubling the total number of such tests published in the entire art therapy literature. Reliability and validity tests have been reported infrequently regarding other art therapy assessments (Elin & Nucho, 1979; Ferguson & Debevec, 1990; Hiltunen, 1990; Levick, 1983; McGlashan, Wadeson, Carpenter, & Levy, 1977; McIntyre & Wright, 1979; Rubin, Schachter & Ragins, 1983; Silver, 1990). Because documenting reliability and validity is “essential” and of “overreaching importance” (APA, 1974, p. 16), such tests were among the earliest work with the DDS. Where an assessment is presented without such substantiation, both clinician and researcher must ask whether the instrument and results have value and are worthy of acceptance and further exploration (Lyerly, no date).