ABSTRACT The Nelore breed is the second largest bovine breed in the world and has actively participated in the expansion of new Brazilian agricultural frontiers. In this context, the purpose of this study was to determine the hematological and biochemical reference intervals of healthy Nelore matrices raised under an extensive regime without supplementation along southwest of Piauí state. Blood samples were collected from fifty-five multiparous female of the Nelore breed. Biochemical and hematological parameters were analyzed using a parametric statistical method with 95% CI of reference limits. The average values of red blood cells, hemoglobin as well as hematimetric indices showed reference ranges similar to reference standards. The hematocrit as well as granulocytes and agranulocytes presented alterations typical of animals raised in environments with higher temperatures. Mineral, enzymatic, protein and metabolic profiles were similar to other bovine breeds but with a narrower range of values. However, lower mean values were observed for levels of ionized calcium, total protein and urea. Nelore females present slightly different biochemical and hematological profiles from other breeds, which might result from the environmental and nutritional management applied and the natural deficiency of nitrogen, phosphorus and calcium in the region's pastures.