An entomological search for vectors of Chagas` disease was performed in 157 houses located in 4 endemic regions of the Central Plateau of Costa Rica. Thirteen of the houses (8.3%) were positive for Triatoma dimidiata(Hemiptera: Reduviidae) the only triatomine species found. The bugs were collected mainly in peridomestic piles of firewood (95.2%) and 8.1% of all the insects were infected by Trypanosoma cruzi. The low abundance of Chagas' disease vectors and the their low infestation rates could be attributed to the improvement of the living conditions in the four study zones. The data also suggests that the impact of T. cruzi infection in Costa Rican populations could be low and the prevalence of T. cruzi could be linked to zoonotic cycles.