The invasion of the Bolivian Jungle has brought the new colonists some unfamiliar diseases, among which we study Leishmaniasis. A previous study described the situation in Yapacaní. Departamento of Santa Cruz, a primary rain forest lowland area. We now focus on the characteristics of Carrasco Tropical, close to a hilly territory of the andean mountains. We studied 11 localities ("colonies") grouped as unions with different lengths of residence in the area. We considered males and females over 15 years old as "at risk" and studied in them all forms of leishmanial infection, through clinical and laboratory (smears) means, including the Montenegro Skin Test (IDRM). Cutaneous ulcers and scars were seen in 2.9% (10 patients of 339 at risk, 6 from "27 de octubre", a younger settlement, 4 from the older Tamboradas): mucocutaneous lesions in 3 (1 from the younger settlement); and skin scars alone in 10.3% (35 from the younger area). The only 2 females with positive findings in the study were seen in this latter group. Transmission is apparently associated with the primary forest which exists at the foot of the Andes in the area, which is visited preferentially by young men.