Children's speech and language development is measured by performance on standardized articulation tests. Test items on these assessments, however, vary in length and complexity. Word complexity was compared across five articulation tests: the Assessment of Phonological Patterns-Revised (APP-R), the Bankson-Bernthal Test of Phonology (BBTOP), the Clinical Assessment of Articulation and Phonology (CAAP), the Goldman-Fristoe Test of Articulation (GFTA), and the Assessment of Children's Articulation and Phonology (ACAP). Four groups of word complexity were used, using the dimensions of monosyllabic vs. multisyllabic words, and words with consonant clusters vs. words without consonant clusters. The measure of phonological mean length of utterance (Ingram, 2001), was used to assess overall word complexity. It was found that the tests varied in number of test items and word complexity, with the BBTOP and the CAAP showing the most similarity to word complexity in spontaneous speech of young children. On the other hand, the APP-R used the most complex words and showed the least similarity. Additionally, case studies were analyzed for three of the tests to examine the effect of word complexity on consonant correctness, usedin the measures of Percentage of Correct Consonants (PCC) and the Proportion of Whole Word Proximity (PWP). Word complexity was found to affect consonant correctness, therefore affecting test performance.