Pairs of speech-language pathologists independently rated severity of phonological impairment for 45 preschoolers, aged 30 to 65 months. Children were rated along a continuum from normal to profound. In addition to judging overall severity of impairment, the clinicians provided separate ratings based on citation form and conversational samples. A judgment of intelligibility of conversational speech was also required. Results indicated that interclinician reliability was adequate (80% agreement) for older preschool-aged children (4-1/2 years and above) but that judgments by speechlanguage pathologists were not sufficiently reliable for children under 3-1/2 years of age 40% agreement). Children judged to have age appropriate phonological abilities were not clearly distinguishable from children judged to have a mild delay. Educating speech-language pathologists regarding the normative phonological data that are available with respect to young preschoolers, and ensuring that such data are readily accessible for assessment purposes, is required.