Experimental research was carried out at the Parasitology and Chemistry laboratories of the Jorge Basadre Grohmann National University, in Tacna. The process involved two phases: (1) determination of the minimum inhibitory concentration (MIC) of Cucurbita Maxima as an antiparasitic agent using canine tapeworms with an intestinal isolation of 5 to 6 hours, and (2) determination of the side-effects of Curbita Maxima on exposed albino rats. It was found that the MIC of 23 gr. of pumpkin seed in 100 ml. of distilled water can produce an antihelminthic effect. This concentration is equivalent to +/- 73 pumpkin seeds (x2 = 5.6, p<0.01). Macroscopically, alterations in helminthic motility are present at a dose of > 23 gr. There is a protheolithic effect with an average survival time of 38.4 minutes. Microscopically the mature proglottids present a destruction of the tegument involving the basal membrane. In the gravid proglottids there is egg destruction. These findings are accentuated when experimenting with Cucurbita Maxima in a concentration of 30 and 32 gr. Superficial non-erosive gastritis was found in weys rats after 4 hours of administering 9 gr/kg.