Cardiovascular events in hypertensives are associated with elevated average blood pressure (BP) and higher short-term BP variability (V), but little is known on treatment effects on BPV and on how to assess changes in short-term BPV. Aim of our study was to address the methodology of short-term BPV assessment and its reduction by Lercanidipine (L) or Enalapril (E) and their combination, through analysis of 24-hour ambulatory BP recordings from two studies including subjects of different age. Study-1: 64 middle-age hypertensives (52.9 ± 9.5 yrs) received L and E s.i.d. at 10 mg (L10, E10) or 20 mg doses (L20, E20) for 8 weeks. Study-2: 66 elderly hypertensives (65.5 ± 4.7 yrs) received placebo, L10, E20 and L10 + E20 s.i.d. for 4 weeks. In middle-age subjects, both L and E decreased mean BP and, at the highest dose, also short-term BPV. In elderly subjects, L10 alone or in combination with E20 reduced BPV. Treatment-induced reductions in BP levels and BPV were uncorrelated. Different methods for short-term BPV assessment did not always provide superimposable results in the elderly. Our study supports a better reduction of BPV by L in the elderly and by E + L combination at any age, suggesting BPV reduction to be independent from reduction in average BP.