This paper presents results from an experiment to study the leaching of the B. H. C. in a type of soil named "arenito Bauru". The B. H. C. was put in a monolythic lysimeter of undisturbed structure which received measured amounts of distilled water. The whole percolate was analysed in its contents of B. H. C. Later on the lysimeters were opened and the soil was analysed in different depths. The results obtained showed that the B. H. C. (isomerous gama) was not leached under the conditions of the experiment; 90 per cent of the total B. H. C. was retained in the upper 10 cm of the soil.