The aim of this study is to present patients, to discuss causes of morbidity and mortality, and to ascertain prognostic indexes and therapeutic options influencing outcome of patients with intestinal obstruction caused by Ascaris lumbricoides.During the past 20 years, between 1975 and 1995, a total of 17 patients with intestinal obstruction attributable to A. lumbricoides underwent surgery. Five were adults, and 12 were children. The most frequent symptoms and physical findings were abdominal pain, distention, nausea, vomiting, and constipation. Enterotomy was performed in ten patients and resection in two patients. Manual exposition and advancement of the parasitic bundle toward the colon was attempted in five patients. Morbidity and mortality rates were 29 and 17 percent, respectively, and septic shock was the major cause of death.This study suggests that simple bowel obstruction is the fatal complication of A. lumbricoides infestation, which is seen particularly in pre-school and young school-aged children living in unhygienic conditions, and illustrates the need for heightened awareness of A. lumbricoides by the emergency physician in the differential diagnosis.Early diagnosis and surgical intervention are essential to minimize high morbidity and mortality.