To assess the standard nasalance scores for normal Thai children in their native language, we organised a prospective descriptive study at the Ear, Nose, and Throat Outpatient Department, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University. Emotionally stable, healthy school children (n = 188) between Grades 1 and 6 with normal intelligence were enrolled in the study. The students were randomly selected according to their economic status. Each subject was asked to read three standard Thai passages: the first devoid of nasal consonants, the second having a mixture of oral and nasal consonants, and the third full of nasal consonants. A nasometer was used to analyse the scores. The mean (SD) percentage scores for the three groups were 14.3 (5.8), 35.6 (5.9), and 51.1 (6.4), respectively, similar to scores for the English language. Extraneous influences on the scores such as sex were considered but were not significant. The passages proved suitable for use as a baseline for the assessment of velopharyngeal insufficiency and rehabilitation planning in Thai children.