The aim of the study is to present usefulness of Cardiac Magnetic Resonance (CMR) to assess left ventricular hypertrophy in hypertensive patients. 48 patients were examined (24 females and 24 males) from 37 to 75 years of age (mean age was 56 years) with diagnosed cardiac hypertrophy in the course of 2nd and 3rd degree primary hypertension. All patients from this group underwent Cardio MR examination using MR 1.5 T Signa Excite (GE) system. Dedicated software was used for post-processing (MASS, Medis). We assessed left ventricular functional parameters such as: Ejection Fraction (EF), End-Diastolic Volume(EDV) and End-Systolic Volume (ESV). We also assessed left ventricular diameters as well as left ventricular posterior wall (PWD) and interventricular septum (IVSD) thickness. We also calculated left ventricular mass (LVM) and left ventricular mass index (LVMI). In most cases (66.7%) patients had significant increase of LVM. On the base of LVMI hypertrophy of the left ventricle was found in 6.2% patients. We affirmed statistically significant changes of left ventricular's morphological and functional parameters. The significant correlation was found between posterior wall diameter (PWD) and LVM, as well as between interventricular septum (IVSD) and LVM. The significant correlation was found between posterior wall diameter (PWD) and left ventricular Ejection Fraction (EF) and End-Systolic Volume (ESV). Cardio MR is an effective method to detect left ventricular hypertrophy (LVH) in hypertensive patients.