The objective was to quantify enteric methane (CH₄) emissions from Holstein cows of 2 levels of milk production in tropical environment and compare data observed in this study to data obtained from the equations proposed by the Intergovernmental Panel in Climate Change (IPCC). The study was carried out at the Universidade Federal de Viçosa, Brazil. High milk production cows (29 ± 0.89 L/d, n = 6) and low milk production cows (10 ± 0.34 L/d, n = 5) were used in the assays. Each assay had the first 5 d for cows’ adaptation plus the number of days required to have 5 d of gases samples of each animal. Cows were held in free stall barns. High production cows diet were constituted, in dry matter (DM) basis, by 48.5% of corn silage, 1.5% of Coast-cross (Cynodon sp.) hay and 50% of concentrate based on corn and soybean meal. The diet of low production cows were in DM basis, 80% of corn silage and 20% of concentrate based on corn, soybean meal and wheat meal. Food and refusals were sampled to dry matter ingestion (DMi) analyses. Average feed intake observed to each group of cows were, respectively, 20.14 e 13.13 kg of DM/day. The sulfur hexafluoride (SF₆) tracer methodology was used to obtain the observed methane emissions. IPCC Tier 2 equations were used to obtain the calculated methane emissions. A t-test were used for test the differences between the observed and the calculated data. Methane emissions observed from high production cows were 115.67 g CH₄/day, 5.74 g CH₄/kg of DMi and 3.94 g CH₄/L of milk and from low production cows were 174.68 g CH₄/day, 13.30 g CH₄/kg of DMi and 17.22 g CH₄/L of milk. When using the IPCC equations, methane emissions for the 2 groups of cows in g of CH₄/day were 403.08 and 261.15, respectively. There are significant differences (P < 0.01) between the observed and the calculated methane emissions data for the 2 groups of cows. It was concluded that the equations for estimating methane emissions from IPCC are not representative for high and low production cows in tropical environment.