en پژوهشي Original Research Articles <p style="text-align: justify;"><strong>Objectives:</strong> The Gradual Increase Length and Complexity of Utterance (GILCU) therapy&nbsp;method is a form of operant conditioning. This is a precise and controlled treatment that is done in 54 steps in 3 speech situations consisting of monologue, reading, and conversation. This&nbsp;study aimed at examining the effects of GILCU treatment method on the reduction of speech&nbsp;dysfluency of school-aged children with stuttering.<br> <strong>Methods:</strong> In this quasi-experimental study, 32 children with stuttering (6-11 years old) who&nbsp;were referred to speech therapy clinics were selected using convenience sampling. Then, they&nbsp;were assigned into two groups. The first group was treated by GILCU therapy method by&nbsp;the researcher, and the second group was treated by traditional methods by another speech&nbsp;therapist. Both groups had fourteen 45-minute sessions that were conducted one to two times&nbsp;per week. Pre-test and post-test of both groups were assessed using the SSI-3 scores. The&nbsp;obtained data were analyzed using the Kolmogorov-Smirnov, t-test, and covariance test.<br> <strong>Results:</strong> Both groups had statistically significant difference (P<0.005) in the stuttered syllables&nbsp;frequency. The average of moments of stuttering from the maximum moments of stuttering&nbsp;and the physical activity were examined according to the speech situations such as reading&nbsp;and conversation. The first group (GILCU therapy method) did not show any statistically&nbsp;significant improvement (P>0.005) with respect to parameters of SSI-3 scores.<br> <strong>Discussion:</strong> These results suggest that a non-programming treatment for stuttering may be&nbsp;effective with school-aged children who stutter.</p> Gradual increase in length and complexity of utterance (GILCU), Dysfluency, SSI-3, School-aged children 59 62 http://irj.uswr.ac.ir/browse.php?a_code=A-10-201-10&slc_lang=en&sid=1 Masume Basi basie.masume@gmail.com Yes Department of Speech Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Morteza Farazi No Department of Speech Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Enayatollah Bakhshi No Depatment of Statistics, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.