PIP: The control of intestinal roundworms, particularly in developing countries including the Philippines, is difficult due to poor environmental sanitation and personal hygiene, lack of health education and adequate supply of potable water and the low socioeconomic status of the people in these countries. Ascaris is the most common parasite of man in both temperate and tropical countries. About 900 million of the world's population are affected. The most frequent complaint of people with ascariasis are vague abdominal discomfort and colicky pains in the upper abdomen. In addition to a variety of medical and surgical problems, the adult worms steal food nutrients from the host causing loss of appetite, faulty absorption, and loss of weight. The most effective means of controlling these common intestinal worms is a combination of personal hygiene, sanitary disposal of body waste, health education and environmental sanitation, an adequate supply of potable water and mass treatment of the population. Because poverty, ignorance and lack of discipline are prevalent, it is not possible to apply all these factors simultaneously. Mass treatment together with personal hygiene and proper disposal of human waste are sufficient for effective control. Recent research work compared 3 different methods of treatment. The findings suggest that mass treatments of a community given 3 times each year at 4 month intervals for a period of 3 years appears to be the most effective in controlling intestinal worms.