['Few epidemiological investigations evaluated the role of smoking cessation on blood pressure (BP), and the results are not univocal. Therefore, the aim of this study was to assess the effect of smoking cessation on the risk to develop hypertension (HPT) and on BP values.', 'This longitudinal study, with a follow-up period of 8 years, included the participants of the Olivetti Heart Study. Participants were 430 untreated normotensive non-diabetic men with normal renal function, examined twice in 1994-95 and in 2002-04. The sample included current smokers (S, n = 212), former smokers (ES, n = 145) and never smokers (NS, n = 73) at baseline.', 'Basal body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly higher in ES than in S (ES vs. S; BMI: 27.0 ± 2.5 vs. 26.1 ± 2.9 kg/m2; P < 0.01; SBP/DBP: 121.2 ± 9.3/80.0 ± 5.8 vs. 19.1 ± 9.9/77.4 ± 6.7 mm Hg; P < 0.05; M ± SD). After 8 years of follow-up, BP changes (Δ) were significantly lower in ES than in S (ΔSBP/DBP: 12.6 ± 13.4/7.9 ± 8.1 vs. 16.0 ± 14.9/10.3 ± 10.1 mm Hg; P < 0.05; M ± SD), also after adjustment for potential confounders. Moreover, at the last examination, the overall HPT prevalence was 33%, with lower values in ES than in S (25 vs. 38%, P = 0.01). After accounting for age, BP and BMI at baseline, and changes in smoking habit over the 8-year period, ES still had significant lower risk of HPT than S (odds ratio 0.30, 95% confidence interval 0.15-0.58; P < 0.01).'] Is not smoking associated with lower risk of hypertension : results of the Olivetti Heart Study?