The burden of rotavirus infections greatly affects the low-income African countries. In the absence of epidemiological data on pediatric diarrhea in São Tomé and Príncipe (STP), a study was conducted from August to December 2011. Rotavirus antigen was detected in 36.7 % of the collected fecal samples (87/237). G8P was identified as the predominant genotype (71.1 % detection rate), while G1P represented only 8.4 %. Phylogenetic analysis of VP7 G8 strains showed clustering within lineage G8d, while VP4 P strains clustered within lineage 1a. Our results represent the first report on rotavirus from STP and show one of the highest detection rates of G8 rotaviruses worldwide.