The efficacy and safety of the HMG-CoA reductase fluvastatin was investigated in a multicenter, open label clinical therapeutic trial in the treatment of hypercholesterinaemia in hypertensive patients (WHO I-II.). 49 patients were involved, 6 patients were dropped out because of th lack of compliance, 43 patients were investigated (mean age: 57.6 +/- 9.4 years, mean blood pressure: 146 +/- 16/88+/- g mmHg (systolic/diastolic). The antihypertensive treatment was unchanged during the study. An 8 weeks low-lipid diet was started if the fasting total cholesterol (TC) level was equal or higher than 6.5 mM/L and the triglyceride level was lower than 4.6 mM/L. After the dietary period fluvastatin treatment was started (20 mg o.d.), if the level of LDL-C was higher than 4,1 mM/L. Blood pressure, heart rate, TC, HDL-C (HDL2-C, HDL3-C), apoA1, apoB, TG were measured at the 4th, 8th, 12th weeks of treatment. LDL-C was calculated with Fridewald equation. The daily dose of fluvastatin was increased to 40 mg, if LDL-C level was higher than 3.5 mM/L after 4 weeks of treatment. 36 patients completed the study (Group B). 7 patients were dropped out at the end of the dietary period, because of the significant decrease of TC and LDL-C levels (Group A). In Group B fluvastatin significantly reduced the level of TC (from 7.22 +/- 0.88 to 5.99 +/- 0.98 mM/L), of LDL-C (from 5.13 +/- 0.71 to 3.95 +/- 0.88 mM/L), and the level of ApoB (from 0.97 +/- 0.26 to 0.85 +/- 0.15 mM/L), but did not influence significantly the level of HDL-C, ApoA1 and TG. The diastolic blood pressure decreased significantly during the dietary period, while after beginning the fluvastatin treatment the decrease of the systolic blood pressure became significant. There was no change in the heart rate. Only minor side effects were observed in 3 patients (dysuria, constipation, lack of appetite). Fluvastatin proved to be an effective and well-tolerated drug in the treatment of hypercholesterinaemia in hypertensive patients.