Objective: Purpose of this study was to compare the results of omentoplasty versus tube external drainage in management of post - operative residual cavity in hydatid cyst liver. Study Design: Prospective Observational case series study. Place and Duration of study: This study was conducted in surgical unit-I Ghulam Mohammad Maher Medical College Hospital Sukkur from January 2003 to December 2007. Material and Methods: Between 2003 and 2007 one hundred and ten patients of hydatid cyst were operated in our institute. Patients having primary hydatid cyst in liver were included in study. Patients with recurrent cysts, cysts with rupture in biliary tract/abdominal cavity and with associated extrahepatic cysts were excluded from study. Out of 110 patients 60 were treated by omentoplasty and 50 with external tube drainage. Both groups of patients were followed for morbidity, mortality and hospital stay in ward. Findings were recorded on profarma. Results: This study included 110 patients with hydatid cyst of liver. Out of 110 cases 45 patients were male and 65 were females. The mean age of patients was 35 years (range 20-63 years). Overall morbidity with omentoplasty was 9% and that with external tube drainage was 31percent. The mean hospital stay of external tube drainage patients was significantly longer (12.7 days) than those treated with omentoplasty (6.3 days). Hospital mortality rate was 2.7% (three patients). One patient, with tube drainage, developed severe sepsis and died on fifth post operative day due to multiple organ failure. Two patients had omentoplasty developed acute myocardial infarction and could not survive. The hospital mortality with omentoplasty group was not related to surgical procedure rather it was related to ASA class and old age of patients Conclusion: We conclude that omentoplasty is safe, effective and easy to perform. It is superior to external tube drainage in uncomplicated hydatid cyst of liver.