This study was carried out to detect Parvovirus B19 (PB19) DNA together with its antibodies in the sera of children with a range of hematological disorders to clarify the contribution of this infection to changes observed in hematological picture in those populations. This study included 85 pediatric patients with different hematological disorders. Twenty healthy subjects with matched age and sex were included as controls. Patients were classified into four groups; group I included 25 patients with hemolytic anemia in aplastic crisis, group II included 20 patients with hemolytic anemia without aplastic crisis, group III included 20 acute leukemia patients under chemotherapy, group IV included 20 patients with recently diagnosed acute leukemia. Virological study for PB19 included determination of specific IgG & IgM together with viral DNA by polymerase chain reaction (PCR). In all groups of patients with positive markers for PB19, there were statistically significant differences in the mean Hb concentration and RBC count (P < 0.001 for each), presence of neutropenia (P = 0.003) and lymphocytosis (P < 0.001) compared to controls. There was statistically significant difference in the prevalence of PB19 IgM, IgG and PCR among studied groups compared to control group. In group I and group II IgG had the highest positive rate (56 and 35%, respectively). In group III IgG also had a high positive rate (45%). However, in group IV IgM had the highest positive rate (50%) followed by PCR (45%) then IgG (40%). In conclusion, PB19 infection is detected in high rates among children with hematological disorders. PB19 must be suspected and screened for when there is anemia in those patients associated with neutropenia and lymphocytosis. In patients with acute leukaemia under chemotherapy who have unexpected anemia, neutropenia and lymphocytosis Parvovirus infection should be considered before a change of chemotherapy protocol. Screening of blood for PB19 may be helpful in understanding the epidemiology of infection with this virus. The direct detection of DNA by PCR in sera needs to be coupled with serology for a more reliable diagnosis of PB19 infections in these children.