Between July and October of 2003, 2004, and 2005, outbreaks of acute gastroenteritis occurred among children <5 years of age in Kinshasa, Democratic Republic of the Congo. Stool specimens (67 in 2003, 108 in 2004, and 116 in 2005) were collected and screened for rotaviruses using either latex agglutination (Diarlex LAA; Orion Diagnostics) or enzyme immunoassay (IDEIA; DakoCytomation). The molecular characteristics of the rotavirus strains were then determined. Group A rotavirus was detected in 195 (76%) of 258 stool specimens. Polyacrylamide gel electrophoresis was used to observe the 11 rotavirus double-stranded RNA segments in 83% of the 195 rotavirus-positive specimens. Six rotavirus group A electropherotypic patterns were noted, predominantly within the short classic pattern (111 [69%]) and the long pattern (37 [23%]). Mixed patterns were noted in the 14 remaining specimens (9%). Of the 29 samples subjected to subgrouping VP6 enzyme immunoassay, subgroup I predominated. Some of the specimens collected in 2003 (n p 26), 2004 (n p 38), and 2005 (n p 52) were analyzed by reverse-transcription polymerase chain reaction, which showed that t G8P and G8P strains predominated in 2003, and G1P strains with short electropherotypic patterns predominated in 2004 and 2005. The emergence in Kinshasa of G8 serotypes, unusually associated with the P genotype, as well as uncommon G1 rotavirus strains showing a short RNA pattern, is significant in relation to the introduction of a rotavirus vaccine and underscores the need for continued rotavirus serotype surveillance in the Democratic Republic of the Congo.