Backgrand and Aim: The measurement of speech intelligibility refer to determining the measure of speech intelligibility in communication. The speech intelligibility is used for decision-making in intervention, the determination of intervention goals, and the measurement of intervention outcomes. This study aimed to investigate the speech intelligibility among the children aged 36 to 60 months.

Methods: In this cross-sectional study, 360 healthy children (180 girls and 180 boys) were chosen among children of kindergardens in Khorramabad city, Iran. Speech sample of subjects was collected by calling pictures of Hydari et al 2010, speech intelligibility measurement test (2010). The voices of the subjects were tape-recorded and speech intelligibility of children was studied within 12 age-groups arranged by two months.

Results: The minimum speech intelligibility was concerned to 36 and 37 months old and the maximum was concerned to 58 and 59 months old. There was a significant differences among age-group 36 and 37 months old with 44 and 45 months old and above, age-group 38 and 39 months old with 55 and 54 months old and above, and age-group 40 and 41 months old with 58 and 59 months old (p<0.05 for all). There was no significant difference among other age groups. There was no significant difference between boys and girls.