Giardiasis is an infection of the small intestine caused by the protozoan parasiteGiardia intestinalisand one of the most common parasitic intestinal diseases in humans worldwide. It mainly manifests as a self-limited illness in the case of immunocompetent patients and usually does not require treatment. However, immunodeficiency is a risk factor for the onset of severeGiardiainfection. In this report, a case of recurrent giardiasis refractory to nitroimidazole therapy is presented. A 7-year-old male patient with steroid-resistant nephrotic syndrome came to our hospital because of chronic diarrhoea. The patient was on long-term immunosuppressive therapy. Microscopic examination of stool showed a significant number of trophozoites and cysts ofG. intestinalis. Treatment with metronidazole for longer duration than recommended has failed to clear the parasite in the present case.