To study whether the cows’ ranking based on methane (CH₄) emission is defined by the host animal irrespective of dietary strategy, 100 Nordic Red cows in mid-lactation were ranked according to CH₄/DMI emission using respiratory chambers. Two groups of 5 low- and 5 high-emitters were selected, fitted with rumen cannulas and subjected to different diets in 3 35-d periods. High grass (HG, 70:30), low grass (LG, 30:70) and red clover (RC, 50:50) based-diets differing in forage to concentrate ratio were fed. Proc GLIMMIX of SAS was used to analyze the data with a model that included random effect of cow, fixed effects of period, diet, group, and interaction of diet and group. Intakes of DM and gross energy tended (P ≤ 0.12) to be lower for the low- compared with high-emitter cows (23.7 vs 25.5 kg/d and 421 vs 455 MJ/d). Intakes of DM and gross energy were higher (P < 0.01) for LG compared with HG and RC (26.5 vs 23.4 and 23.7 kg/d; 476 vs 416 and 423 MJ/d). Intake of NDF was higher for HG compared with LG and RC (8.65 vs 7.95 and 7.78 kg/d; P < 0.01). Both groups had similar milk yield. HG had lower milk yield than LG and RC (34.2 vs 39.3 and 38.4 kg/d; P < 0.01). Digestibility of OM (71.4 vs 73.0%; P < 0.01) and NDF (55.6 vs 59.2%; P < 0.05) was lower for low- compared with high-emitters. Low-emitters tended (P = 0.08) to have lower CH₄/DMI than high-emitters (20.9 vs 22.5 g/kg). LG had lower CH₄/DMI than HG and RC (19.7 vs 23.4 and 22.0 g/kg; P < 0.01) and the interaction of diet and group was not significant. High-emitters consuming HG and LG had higher CH₄ emission (g/d) than low-emitters consuming LG (581 and 580 vs 466 g/d; P = 0.06 for group × diet interaction). Rumen DM fill, measured by rumen evacuation, did not differ between diets or groups but rumen NDF fill was lower for LG than HG (6.47 vs 7.35 kg; P < 0.01). Rumen molar acetate to propionate ratio was lower for LG compared with HG and RC (2.76 vs 3.49 and 3.46; P < 0.01). This ratio tended to be lower for low- than high-emitters (3.09 vs 3.39; P = 0.09). The results suggest that CH₄/DMI ranking of cows is determined by the host animal irrespective of the diet fed.