Objective: The aim of this study was to evaluate the safety and efficacy of transcatheter atrial septal defect (ASD) closure guided by fluoroscopy and transthoracic echocardiography (TTE) and to present our experiences. Material and Methods: In this study, we evaluated 108 patients’ files taken to the catheter laboratory for transcatheter ASD closure retrospectively. The procedure was abandoned in ten patients because of septum device disproportion (6) and deficient rims (4), mainly inferior vena cava rim. Results: Transcatheter ASD closure guided by TTE was performed in 98 patients (59 female). The mean age of patients was 9.5±6 years (2.6-46), and the mean weight was 30.3±15.3kg (12-80). TTE-guided ASD closure was successfully performed in 92 of 98 (94%) patients. The median largest ASD diameter measured by TTE was 10.75 mm (interquartile range (IQR) 9.12-14. The median stretched balloon diameter measured by fluoroscopy was 14 mm (IQR 12.4-18). The median device waist diameter was 14 mm (IQR 13-18), the median device left atrial (LA) disk diameter was 28 mm (IQR 26-31), and the median ratio of LA disc diameter to total septal diameter was 75% (IQR 68-81). The median fluoroscopy and procedural times were 8 minutes (IQR 5.6-13.75) and 36.5 minutes (IQR 30-49) respectively. Conclusion: Transcatheter ASD closure guided by TTE and fluoroscopy is safe and effective in children, adolescents, and young adults.