Previous studies in Jeddah, western Saudi Arabia, showed rotavirus (RV) prevalence around 40% in pediatric inpatients with gastroenteritis (GE) with a maximum level during cooler months. Currently, there are no data on impact of rotavirus vaccine (RVV) on RV-GE in Saudi Arabia. Therefore, this study was conducted to assess impact of RVV on incidence and severity of RV-GE in hospitalized pediatric patients; 3 years after introduction of RVV in Saudi immunization program (SIP) in January, 2013.This cross-sectional observational study included GE cases under 5 years of age admitted to 2 tertiary hospitals, in Jeddah, from October to December, 2015. All included GE-cases had RV antigen detection in stool by immunochromatographic assay, complete data collection including RVV status and severity assessment (Vesikari score) in initial admission.During study period, a total of 359 GE cases in children under 5 years of age were hospitalized with 14 (3.9%) RV-GE confirmed cases. Mean age of RV-GE patients was 13.10 ±â€Š5.70 months. All RV cases had severe GE and 1 case received RVV. Among other 345 GE cases, 35.7% did not receive RVV and 46.1% had severe GE. Severe GE (Vesikari score > 11) was more significantly identified among RV-GE cases than in other all-cause GE (P < .001). During same period of this study in 2012, 369 RV-GE out of 1193 total GE cases (31%) were hospitalized at 2 hospitals, so, number of hospitalized pediatric patients for all-cause and RV-GE in children under 5 years of age decreased significantly in 2015 RV season (compared to 2015 RV season, odds ratio for RV-GE in 2012: 11.04, 95% CI: 6.38-19.09).Logistic regression analysis of variables of this cross-sectional, hospital-based study in Jeddah, Saudi Arabia, 3 years after introduction of RVV in SIP, showed that among the studied variables, RVV was associated with remarkable reduction of hazard of all-cause and RV-GE in vaccinated and even in unvaccinated children under 5 years of age possibly by RVV herd effect. However, RV was still associated with severe GE-related hospitalizations in unvaccinated children against RV who were younger than 2 years and particularly in the 1st year of life, indicating need for more optimum rate of RVV coverage. Hopefully, further improvement in RVV coverage rate may make RV-GE a disease of the past in Saudi children.