Mixed infections of enteric viruses and parasite can infected the human alimentary canal and quite complex physiological changes can result from such infection. To study the association between enteric viruses and giardiasis among diarrheal children as well as to clearly the relationship with Giardia lamblia genotypes in Diyala province, Iraq. Descriptive cross sectional study was conducted in Al-Batool Teaching Hospital for Maternity and Children in Baqubah city, during the period from June 2017 till November 2017. One hundred and sixty stool samples were collected from children with gastroenteritis using a clean and dry container. Samples, screened for rotavirus, adenovirus, astrovirus and norovirus using Cer Test Biotec, and G. lamblia by ELISA kits. The positive G. lamblia samples were further analyzed by nested polymerase chain reaction. Rotavirus was detected in 20%, adenovirus in 18.75% and norovirus in 13.75% while no positive result with astrovirus. G. lamblia were detected in 42 cases (26.25%), amplification triose phosphate isomerase (tpi) gene was successful in 28/42 (66.66%) samples, 8 (28.57%) contained genotype A and 20 (71.43%) samples contained genotype B. The majority of infected children were males less than five years old. Rotavirus infection rate amongst children in Diyala appears to be relatively higher than other enteric viruses. Co-infection with G. lamblia type B have important role.