Objectives: Investigating the prevalence of speech and language disorders and the contributing factors can help determine the best treatment options suited to the needs of these patients. So far, no comprehensive study has been conducted on screening speech and reading disorders and Problems in the Structure and Function of Articulation Organs (PSFAOs) in children in Mashhad City, Iran. This study aims to screen for these disorders and investigate the effects of demographic factors on such disorders. Methods: Via the stratified-cluster sampling method, 2770 native Persian-speaking children participated in this study, of whom 1381 were girls and 1389 were boys, ranging from preschool to the third grade (3 to 9 years old). After obtaining the demographic information, the PSFAOs screening was performed for all participants using a semi-structured questionnaire taken from Paul et al.’s report (2017). Screening for a grade of dysphonia was then carried out for children with suspected voice disorders using the grade, roughness, breathiness, asthenia, and strain test. Fluency of speech screening for children with suspected fluency disorders was performed using the stuttering severity instrument – fourth edition test, and screening of reading skills for school children was performed using the screening inventory reading test. Analytical analysis was performed via the Chi-square test between study variables, including disorders and other variables. Two types of logistic regression models were used. The data were analyzed using survey data analysis of the Stata software, version 14.1, and P<0.05 was considered significant. Results: The prevalence of articulation disorders, voice disorders, stuttering, PSFAOs, reading disorders, and multiple disorders (presence of two or more disorders per person) was 1.62%, 1.99%, 1.69%, 1.1%, 8.21%, and 14.89%, respectively. Descriptive analysis showed that the prevalence of articulation disorders, voice disorders, stuttering, and multiple disorders was higher in boys compared to girls (P=0.000), while the prevalence of reading disorders and PSFAOs was higher in girls (P=0.000). Furthermore, articulation disorders and reading disorders were more common in first-graders. The prevalence of voice disorders, stuttering, and PSFAOs were higher in the third graders. The logistic regression analysis showed that boys were more likely to develop speech and language disorders compared to girls (OR=1.3, P=0.01), and first-, second-, and third-graders were less likely to have such disorders when compared to preschoolers (OR=0.8, P=0.03). Discussion: Compared to previous studies, the different rates of prevalence of the disorders studied in this investigation are related to differences in their methodology, the number of samples, age, linguistic and cultural characteristics of the subjects, and individual factors. In this study, the prevalence of the studied disorders was higher in boys, first-graders, and children with families of 4 or more. The development of speech and language skills is different between genders; slower maturation of male brains seems to predispose them to slower development of speech skills. The lower prevalence in school-age children may be because these disorders gradually resolve during the early years of childhood. Moreover, low family socioeconomic status and family size may be the contributing factors to speech and language disorders.