BACKGROUND One side effect of antihypertensive drugs is their impact on nutritional status and metabolism. The purpose of this study was to assess the nutritional and biochemical parameters in spontaneously hypertensive rats following treatment with antihypertensive drugs. METHODS The experiment was performed on 50 male spontaneously hypertensive rats (SHR), which were assigned to five groups: control (C), with perindopril (PR), with metoprolol (MT), with indapamide (ID), and with amlodipine (AM). All rats were provided ad libitum standard diet (with or without drugs) and distilled water. After 45 days, the animals were weighed and killed. Liver, kidney, heart, spleen, pancreas, and blood samples were collected. Concentrations of glucose, cholesterol, triglycerides, and albumin were assayed in serum. Morphology parameters, such as white blood cell, red blood cell, hematocrit, and lymphocyte counts were measured in the blood. Blood pressure was measured using a tail-cuff plethysmograph. RESULTS The results obtained indicate that the hypotensive drugs under investigation had no effect on the selected nutritional parameters. Perindopril significantly decreased the relative mass of the heart and amlodipine markedly decreased the relative mass of the pancreas. A markedly higher concentration of glucose in the group with indapamid, and a significantly lower concentration of triglycerides in the group with metoprolol, were observed. Indapamide and amlodipine markedly increased the value of red blood cells and hematocrit in the blood of SHR. CONCLUSIONS Long-term therapy with antihypertension drugs may influence tissue mass and biochemical and morphological status in the body.