The association of Helicobacter pylori (H. pylori) infection and parasitic infections including Giardia lamblia (G. lamblia), especially in childhood, is widely recognized to be high in developing communities. We aimed to study the impact of concomitant intestinal parasitic and H. pylori infections on the different clinical presentation of infected children and whether this coinfection could in turn cause any alteration in the clinical manifestations of each other. This cross-sectional study included 150 children of both sexes with their age ranging from 1 to 15years, having gastrointestinal complaints, throughout 8months duration. All cases were subjected to full history taking, clinical examination and stool analysis by direct wet smear and formalin-ethyl acetate concentration technique, permanent staining with cold acid fast stain in addition to H. pylori coproantigen detection in stool. Parasitic infection was recorded in 58.6% of patients, with G. lamblia the most detected parasite (35.2%). Cases infected with H. pylori were 63 cases (42%) of which 61.9% of cases showed associated parasitic infection. Diarrhea was the most frequent complaint (63.2%) in cases infected with intestinal parasites, while it was less frequently recorded in co-infected cases (35.8%) and in cases with H. pylori infection only (29.1%) (P value 0.0008). On the other hand, vomiting was less recorded in coinfected cases than cases with H. pylori infection. Coinfection with intestinal parasites (including G. lamblia) and H. pylori could modulate the clinical manifestation of each other especially diarrhea in parasitic infections and vomiting in H. pylori infection.