The babassu mesocarp flour (BMF) is produced from the babassu (Attalea speciosa Mart ex), a palm tree native found between Cerrado and Amazon forest in Brazil. It is a by-product of the industrialization of the babassu coconut for the production of edible oil, babassu meal and others. It is important due the significant starch content of the mesocarp. However, epicarp and endocarp contamination can occur during mesocarp extraction, resulting in a BMF with high fiber content and low starch content. Twenty-eight crossbred male goats (25.8 ± 4.2 kg BW) were used in a randomized complete block design to evaluate the effect of increasing levels of BMF on feed intake, digestibility of nutrients and ruminal pH. Goats were confined individually and fed an isonitrogenous diet (12.6 ± 0.1 CP, DM basis) containing 70% of concentrate (compound by ground corn, soybean meal, wheat bran, mineral supplement, limestone and BMF, in diets with this coproduct) and 30% of Tifton 85 hay for 21 d, with 15 d for diet adaptation, 5 d for data collection of orts and total feces, and 1 d for ruminal content collection (0, 3, 6, 9 and 12 h after feeding). A representative sample of ruminal content from each animal was collected via esophageal tube. The first portion of rumen fluid was discarded, and the second portion, after being squeezed through 2 layers of cheesecloth, was used for determining ruminal pH. Increasing levels of BMF were 0, 10, 20 and 30% (DM basis), corresponding to experimental diets 0BMF, 10BMF, 20BMF and 30BMF, respectively. Orthogonal polynomials for diet responses were determined by linear and quadratic effects (P = 0.05). No significant differences were detected for DM (812 ± 224 g/d), CP (106 ± 29 g/d) and OM (770 ± 212 g/d) intake. Also, no differences were observed for DM (79.0 ± 4.1%), CP (76.5 ± 4.8%) and OM (80.0 ± 3.9%) digestibility. However, the NDF intake (245.2, 267.9, 447.6 and 420.6 g/d) increased linearly with increasing levels of BMF in the diet, while NDF digestibility (50.1, 61.3, 63.7 and 60.5% for 0BMF, 10BMF, 20BMF, and 30BMF, respectively) and ruminal pH (6.3, 6.4, 6.5 and 6.5 for 0BMF, 10BMF, 20BMF, and 30BMF) had a quadratic effect. The BMF is an alternative for energy source in goats feed and can be added at levels up to 30%