Preoperative judgement of which children is likely to benefit from endoscopic third ventriculostomy (ETV) is still the most difficult challenge. This study aimed to compare the efficiency of third ventricular floor bowing (TVFB) and ETV success score (ETVSS) in selecting ETV candidates and achieve a better preoperative patient selection method for ETV based on our institutional experience. Children (≤ 16 years old) with newly diagnosed hydrocephalus treated with ETV between January 2013 and June 2018 were included in this prospective study. Patients with TVFB will receive ETV procedure in the pediatric subgroup of our department. ETVSS was calculated in every patient. The ETVSS predicted ETV success rate and the actual ETV success rate in our institution were compared and further analyzed. One hundred twenty-nine children with TVFB were enrolled in our study. The mean age at ETV was 5.84 ± 5.17 years (range, 0.04-16). Brain tumors, aqueductal stenosis, and inflammatory are the most common hydrocephalus etiologies. The most common complication was noninfectious fever (3.1%). During the average follow-up of 19.5 ± 14.95 months, twenty-five patients had depicted ETV failure. The actual ETV success rate (81%) in our study was higher than the success rate (69%) predicted by ETVSS. TVFB is a pragmatic, efficient, and simple model to predict the ETV outcome. We suggest that for hydrocephalic patients with preoperative third ventricular floor bowing, ETV should be the first-treatment choice regardless of the ETV success score. And for patients without such sign, ETVSS should be applied to select ETV candidates.