Objectives: The purpose was to determine the changes in intelligibility and articulation after partial glossectomy in a child with Beckwith-Wiedemann syndrome. Methods: For the assessment of articulation, a speech sample was gathered by means of a picture naming test. The analyses included a description of the child’s sound production regardless of their relation to the adult target, as well as analyses comparing the patient’s pronunciations with the adult form. For the assessment of intelligibility the sample was independently rated by 2 experienced speech pathologists using a nominal scale with four categories. Results and Conclusions: Partial glossectomy resulted in a dramatic improvement of speech. Before surgery the speech was definitely not age-appropriate. The child was capable of producing only 23% of the Dutch consonants. This is far less than expected at that age. After surgery, consonant inventory was almost complete and as such was even more than age-appropriate. The partial glossectomy had obviously a positive impact on both place of articulation and manner of articulation. The analyses revealed a tendency towards vowel speech before surgery along with glottal realizations. After surgery the vowel speech and the compensatory articulation patterns had disappeared. Several factors that contributed to the improvement are discussed.