The aim of this study was to verify the influence of sawdust substrates obtained from wood treated with sodium tribromophenate and not treated of Pinus elliotti, P. taeda, and Araucaria angustifolia in larval cultures of ovine gastrintestinal helminths. Feces samples were collected between 8 to 12am, from a lamb naturally infected with gastrintestinal nematodes and analysed by the modified Mc Master technique for worm egg counting (epg). Six groups of 20g of feces were prepared. Each group received 5g of one of the sawdust substrates and 5ml of distilled water. The material has been processed, identified and taken to a climatized chamber with a temperature of 27 +/- 1 degrees C, relative humidity above 70%, and in escotophase for seven days. The third stage larvae were recovered by the Baermann technique after four hours of sedimentation for the counting and identification of one hundred larvae per treatment. For each treatment were realized 10 repetitions. The average of EPG of Strongylida Order was 630. The average of the larvae number obtained in 20 grams of feces and the percentage of recovery in the different substrates based on the EPG was: P. taeda treated, 2719 (22.66%) and not treated, 2353 (20.08%); P. elliotti treated, 3069 (22.48%) and not treated, 3181 (24.54%); A. angustifolia treated, 2370 (18.73%) and not treated, 3361 (26.75%). There was no statistic difference in 5% level of significance between the averages and the number of larvae in the different substrates.