The purpose of this study was to determine any changes in the rectus abdominis and diaphragm muscles, which are core muscles, in children and adolescents with nocturnal enuresis (NE) using the shear wave elastography (SWE). In this case-control study, the rectus abdominis and diaphragm muscles of 40 children and adolescents with NE and 40 healthy controls were evaluated. The rectus abdominis muscle was examined at the right supra- and subumbilical levels, and the diaphragm at the right 9th-10th intercostal space. The thickness of both muscles was measured by gray scale ultrasound and muscle stiffness was measured by SWE. The demographic characteristics of the patients such as sex and age and their anthropometric measurements including height, weight, and BMI were recorded. Compared to the control group, the NE group had significantly lower mean rectus abdominis muscle stiffness values on both the supraumbilical and subumbilical levels (p < 0.05). There was no significant difference in mean rectus abdominis thickness and diaphragm thickness-stiffness values between the groups (p > 0.05). According to the results of the study, it is thought that NE children have problems with core stabilization and that children with NE should be directed to appropriate treatment. However, future studies are needed with larger sample sizes and other factors that are thought to affect muscle architecture.