Background and Objectives: Giardiasis mainly affects young children causing diarrhea, malnutrition and growth retardation. Due to adverse effects of antiprotozoal treatment such as low compliance with drug therapy, reinfestation, occurrence of resistant strains, headache and metallic taste, the use of natural live bacteriotherapy has been studied. The study was designed to investigate in vitro the colonizing ability of probiotic Lactobacillus rhamnosus GG (LGG) viz-a-viz its ability to inhibit the adherence of Giardia trophozoites to murine enterocytes under conditions simulating the intestinal environment. Materials and methods: Murine enterocytes were harvested and incubated with Giardia trophozoites either prior or simultaneously with probiotic LGG to assess the adhesion using scanning electron microscopy. Results: It was observed that 15% of Giardia trophozoites adhered to enterocytes at 37°C in Hank's Balanced Salt Solution, after 1h of incubation. However, coincubation of murine enterocytes with probiotic LGG either 30 min prior or simultaneously with Giardia trophozoites led to 23-27% reduction in the adherence of Giardia trophozoites compared with 46% adherence in the absence of LGG. Further, scanning electron microscopy also showed in vitro inhibition of Giardia trophozoites to murine enterocytes due to probiotic supplementation. Iterpretations and conclusion: The data suggest the colonizing ability of probiotic LGG to murine enterocytes that modulates murine giardiasis mainly by displacing the Giardia trophozoites.