The authors present the results of trials carried out in the treatment of ascariasis with tetramisole; out of 35 patients given tetramisole cyclamate in a single dose, 82.8% presented parasitological cure; 82.5% of 40 paVents treated with tetramisole hydrochloridre also in a single dose were cured. No side-effects were cbserved with hydrochloridre; with cyclamate 28.6% of the cases showed very mild side-effects. Tetramisole both hy irochloridre and cyclamate salts must be considered the best drug for the treatment of ascariasis.