Sapovirus (SaV) and astrovirus (AstV) are important viral causes of acute gastroenteritis. From 2016 to 2019, 172 stool samples were collected from children with gastroenteritis in Kobe, Japan for sentinel surveillance of infectious gastroenteritis. In this study, we tested 53 of the 172 stool samples that tested negative for other enteric viruses to determine the prevalence of SaV and AstV. The samples were screened for SaV and AstV using real-time polymerase chain reaction. Positive samples were genotyped by sequencing and genetic analysis of partial regions of the capsid and RNA-dependent RNA polymerase. Of the 53 samples tested, 19 (35.8%) were positive for SaV, and three (5.7%) were positive for AstV. Of the total samples, 11.0% (19/172) and 1.7% (3/172) were positive for SaV and AstV, respectively. The most frequently detected genotype of SaV was GI.1, followed by GII.3. The AstV genotypes were MAstV1.1 and MAstV1.4. This study indicates that SaV and AstV are important causes of viral gastroenteritis in children.