Studies were carried out on the action of cyclamate and hydrochloride 2, 3, 5, 6 tetrahidro-6-fenil-imidazo (2,1-b) tiazol in the treatment of ascariasis. Eighty four patients were treated, 48 with hydrochloride and 36 with cyclamate. The percentage of cure with hydrochloride was 83,9 and with the cyclamate 76,4. No side-effects were observed with the hydrochloride while with the cyclamate 53,6% of the patients showed mild symptoms of intolerance. The percentages of cure were similar to those observed with the use of piperazine most commonly used in the treatment of ascariasis.