Hematological parameters and serum ferritin were compared between 179 vegetarians and 58 control subjects using Hematology analyzer H3 and microparticle enzyme immunoassay, respectively. Serum Vitamin B12 was also compared between 68 vegetarians and 30 control subjects using microparticle enzyme immunoassay. It was found that hemoglobin, hematocrit, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, white blood cells, neutrophils, serum ferritin and serum vitamin B12 in vegetarian were significantly lower than control subjects (P < 0.05). In addition, red cell distribution width and lymphocytes in vegetarians were significantly higher than control subjects (P < 0.05). There were 34 cases of iron deficiency in 179 vegetarians (19.%) which can be classified to iron depletion (4 cases), iron deficient erythropoiesis (12 cases) and iron deficiency anemia (18 cases). Vitamin B12 deficiency was found in 27 cases of 68 vegetarians (40%).