Background: Surgical repair for hypospadias is complicated and can present challenges. To minimize the occurrence of these complications, preoperative education of mothers is essential. The aim of the present study was to determine the effect of predesigned instructions for mothers of children with hypospadias on their knowledge, practices, and early postoperative complications. Subjects and method: This study was conducted at Assiut University Children Hospital's pediatric surgery unit; a quasi-experimental research design was used. This trial involved 60 mothers and their children, who were divided equally (30 mothers and their children in each group); data were collected firstly from the control group and then from the study group. Four tools were used to get the data for this study. Tool I: Background information form. Tool II: A questionnaire about mothers' knowledge regarding hypospadias. Tool III: Observational checklist. Tool IV: Postoperative complications sheet. The results of this study detected that there was a positive correlation between mothers knowledge and their practices (r=0.866**) and there was a negative correlation between mothers' knowledge, practices, and the occurrence of postoperative complications (r=-0.503** and -0.460**), respectively. The researchers concluded that the application of predesigned instructions for mothers of children with hypospadias resulted in a significant decrease in the occurrence of postoperative complications. Following the adoption of predesigned instructions, mothers' knowledge and practices in the study group improved compared to the control group. Researchers recommended that a multidisciplinary team should create and carry out educational programs for mothers in order to sustain improved postoperative outcomes for children.