A retrospective clinical study to evaluate the effects of paralyzing vermifuges on the course of intestinal obstructions complicating ascariasis was performed. Forty-two patients, 26 patients with partial and 16 patients with complete intestinal obstructions, were treated over 7 years. Although 24 patients have not received any medications two patients with partial obstructions received flaccid paralyzing agent before referral. However, 12 of 16 patients with complete obstruction received spastic paralyzing agent, and the remaining patients received flaccid paralyzing agent before referral. Paralyzing agents, especially those causing spastic paralysis, should be avoided in patients with abdominal symptoms presumed to be related to ascariasis because of the risk of causing complete obstruction and making surgery more complex.