Hydatid disease (echinococcosis) remains a complex worldwide problem in rural areas. Medical treatment does not definitively cure hydatid cysts, and surgical management aims to eliminate the parasite, favoring rapid disappearance of the residual cavity, preventing complications and recurrence, and shortening the hospital stay. In this consecutive series, 298 patients with liver hydatidosis were treated surgically by the authors from 1950 to 1987 in various hospitals in Rome, Italy. Surgery comprised conservative methods (marsupialization and partial cystopericystectomy) and radical methods (total pericystectomy and liver resection). Liver resection was used only if unavoidable. Complications were exudate from the residual cystic cavity, cholerrhagia, and nonspecific incisional fistula. In the entire series, morbidity was 8.7% of which 12.6% was seen with conservative methods and 5.5% with radical methods (p < 0.05); mortality was 3.6%, of which 5.9% was seen with conservative methods and 1.8% with radical methods (p = NS). Over the 37 years, as medical science and complementary therapies progressed, the use of conservative operations diminished and radical treatments increased. Long-term follow-up showed that hydatid disease relapsed more frequently in patients who underwent conservative or subtotally radical treatment than in those who underwent radical surgery: eight patients (11.2%) versus one (0.9%) (p < 0.01). Hence surgical treatment that removes all of the pericyst and preservation of the nonpathologic liver are important.