Gross- and microscopic- anatomical studies were performed on heart, kidney and adrenal gland of 55 Merino- sheep of various ages and sex. The adult animals in comparison to the juvenile had following variations of age on the studied organs: increase of the heart weight, increase of the nucleus size of the cardiomyocytes and of the endocrinocytes of the Zona glomerulosa, increase of the glomerular size and decrease of the glomerular density. There was no relationship between age and relative heart weight, the content of the intramyocardial connective tissue, the width of the Zona glomerulosa or the width of the Zona externa corticis renalis. The lambs showed sex- specific differences to following studied marks: smaller content of the intramyocardial connective tissue in the ventricular walls and a larger width of the Zona glomerulosa of the adrenal gland of the male animals than the female. Furthermore correlations between heart, kidney and adrenal gland under special consideration of the blood pressure were discussed.