Results of the numbering of T. trichiura, A. lumbricoides et N. americanus eggs found in the stool, taken from a representative sample of the population of Tortuga island, shows the importance of parasital load borne by people attacked by the parasites. Those who produce the greatest number of eggs for a gram of faeces are young children. For adults, the evolution of the parasital load follow that of the prevalence, for each Nematodes, with an increase of the average number of eggs of A. lumbricoides per gram of faeces for adults aged 30 to 44, and of the average number of N. amercanus per gram of faeces for adults aged 45 to 59. Moreover women adults show a higher number of parasites than men. Farmers from villages within the interior of the island who are more often attacked than those from the coast, also bear a parasital load which is twice as high. Victims less than 5 years old and more than 30, particularly women, whose faeces are richest in eggs, seem to present the greatest danger for the transmission of ascaridiosis and necatorosis in Toruga Island.