Authors present a study of 90 patients medicated with Pyrantel Pamoate (Trans-1,4,5,6-Tetrahydro-1-methyl-1-2/2-thienyl) vinyl/pyrimidine) all suffering from intestinal parasithosis, mainly Ascaris lumbricoides and Enterobius vermicularis. Patients were divided in tico groups: the first, consisting of 25 patients who received a dosage of 5mq/kg in one unique dose and at one time; in this group, only the study of the therapeutic action against ascariasis and enterobiasis was considered. In the second group, consisting of 65 patients, a unique dose of 10mg/kg and taken at one time was given and, besides the study of the therapeutic action on ascariasis and enterobiasis, also the study of possible activity on other helminthiasis was observed. All patients, after the medication, were submitted to three procto-parasitological control tests (on the 7th., I5th. and 30th. day) and the previous positive cases suffering from Enterobius vermicularis. were also submitted to the "anal-swab" control test on the 7th. and 15th. day. Authors evidenced in the first group procto-parasitological cure in 13 of the 18 cases suffering from ascariasis (72,2%). For enterobiasis, they obtained a cure of 61.5% and on the associotion of Ascaris-Enterobius, they obtained a cure of 50,0% of both parasites, not existing even one case of total failure on the remaining cases. In the second group, the results obtained were the following: Ascariasis, 50 cases; cured, 40 (80.0%). Enterobiasis. 22 cases; cure of 16 cured (72,7%). Necatoriasis, 8 cases; 5 cured (17,8%). Trichuriasis, 41 cases; cured, 5 (12.1%) . Strongyloidiasis, 5 cases; cured, 1 case (20,0%). Enterobius-Ascaris association, 14 cases; total cure of both parasites in 10 cases (71,4%), 4 cases, partial cure of one or the other parasite, not existing total failure in any. Tablets of 100 to 300mg of active substance and, in liquid form, 10mg of active substance per cubic cm were given. Collateral effects were not important both in number and in intensity: In the first group, 12,2% of the cases referred epigastralgia, dizzyness and diarrhea. In the second group, 23,07% of the cases, predominating epigastralgia, dizziness and cephalea (migraine headache), diffuse abdominal pains and diarrhea. Authors conclude that Pyrantel Pamoate is a very efficient drug for the treatment of ascariasis and enterobiasis, including the association of these two parasitosis. The drug presentes discret collateral effects and is easy to take (small number of tablets, unique dose and in liquid form having very pleasant flavor). They indicate as the ideal dosage 10mg/kg, which, without significantly alterating the intensity and the incidence of collateral efects, gives better therapeutic activity on ascariasis, enterobiasis and the association of these two parasitosis