AIM: To investigate the prevalence of giardiasis in patients with dyspeptic symptoms. METHODS: Clinical records of consecutive patients who attended Gastroenterology Department at Aga Khan University Hospital from January 2000 to June 2003 and had esophagogastroduodenoscopy (EGD) with duodenal biopsies and international classification of diseases 9th revision with clinical modifications (ICD-9-CM) coded with giardiasis were studied. RESULTS: Two hundred and twenty patients fulfilled the above criteria. There were 44% (96/220) patients who were giardiasis positive, 72% (69/96) of them were males and 28% (27/96) of them were females. There were 65% (81/124) males and 35% (43/124) females who were giardiasis negative. The mean age of patients with giardiasis was 28±17 years, while that of giardiasis negative patients was 40±18 years (P<0.001). In patients with giardiasis, abdominal pain was present in 71% (68/96) of patients (P = 0.02) and diarrhea in 29% (28/96) (P = 0.005); duodenitis in 25% (24/96) on EGD (P = 0.006) and in 68% (65/96) on histopathology (P = 0.002). CONCLUSION: Giardiasis occurs significantly in young people with abdominal pain, while endoscopic duodenitis is seen in only 25% of giardiasis positive cases, which supports routine duodenal biopsy. METHODS: Clinical records of consecutive patients who attended Gastroenterology Department at Aga Khan University Hospital from January 2000 to June 2003 and had esophagogastroduodenoscopy (EGD) with duodenal biopsies and international classification of diseases RESULTS: Two hundred and twenty patients fulfilled the above criteria. There were 44% (96/220) patients who were giardiasis positive, 72% (69 / There were 65% (81/124) males and 35% (43/124) females who were giardiasis negative. The mean age of patients with giardiasis was 28 ± 17 years while while of giardiasis negative patients was 40 ± 18 years (P <0.001) In patients with giardiasis, abdominal pain was present in 71% (68/96) of patients (P = 0.02) and diarrhea in 29% (28/96) (P = 0.005); duodenitis in 25% (24/96) on EGD (P = 0.006) and in 68% (65/96) on histopathology (P = 0.002). CONCLUSION: Giardiasis is significantly in young people with abdominal pain, while endoscopic duodenitis is seen in only 25% of giardiasis positive cases, which supports routine duodenal biopsy.