Dicrocoelium dendriticum (the lancet fluke) is less common liver parasite. Adults inhibit bile duct, while characteristic eggs pass in stools. During one academic year, a total of 1196 patients referred to Parasitology Laboratory from King Abdel Aziz University Hospitals, 121 patients were positive for D. dendriticum. The majority was Saudis, and only 32 of the 121 patients (26.4%) had true dicrocoeliosis, as detected by re-examination after three days of liver free diet. The other patients have false Dicrocoeliasis. The infection was influenced by the patients' behaviours. The Saudis consume more sheep meat during month (Du-Elheja) of Haj and Feast. Examination of the slaughtered sheep at the governmental slaughterhouses showed the majority of them have the liver infected (9-24%) with the lancet liver fluke. It is concluded that rate of infection proportionates with the rate of sheep infection and the consumption of infected livers. For proper estimation of human infection should be on diet free liver before examination.