In the Heusler compound Ru2CrSi, an antiferromagnetic transition at T N =14 K was revealed by specific heat and magnetization measurements. In this study the electrical resistivity is measured in magnetic fields up to 14.5 T, and the antiferromagnetic transition in magnetic fields is investigated. In the temperature dependence of the resistivity at zero field, a clear dip at ∼15 K and a hump with a maximum at ∼ 9 K are observed. This dip is considered to be due to the antiferromagnetic transition. With increasing magnetic field, the magnitude of the resistivity slightly increases around T N; i.e., a positive magnetoresistance is observed. The temperature dependence of the resistivity is hardly affected by increasing the magnetic field. The transition temperature decreases only by ∼ 0.3 K even with applying 14.5 T. These results demonstrate that the antiferromagnetic state in Ru2CrSi is unusually unaffected by a strong magnetic field.