<p>This study compared the associations of smoking status assessed by self-report versus urine cotinine with incident hypertension risk. Using the PREVEND study, a prospective cohort conducted in the Netherlands, smoking status was assessed at baseline by self-reports and urine cotinine in participants without a history of hypertension. Participants were classified as never, former, light current (≤10 cigarettes/day), and heavy current smokers (&gt;10 cigarettes/day) by self-report, and analogously by urine cotinine: &lt;100 ng/mL (never), 100–500 ng/mL (former), 501–1456 ng/mL (light current), and &gt;1456 ng/mL (heavy current). Incident hypertension was defined as systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or the initiation of antihypertensive medications. Hazard ratios (HRs) with 95% CIs were estimated. The cohort comprised of 3296 participants (mean age 49 years, 46.0% male). The distribution of participants by self-reported smoking category was: never (n = 1045), former (n = 1271), light current (n = 379), and heavy current (n = 601). Based on urine cotinine, the distribution was: never (n = 2288), former (n = 161), light current (n = 404), and heavy current (n = 443). During a median follow-up of 7.2 years, 832 participants developed hypertension. Compared with self-reported never smokers, the multivariable adjusted HRs (95% CI) for hypertension were 1.03 (0.87–1.23) for former, 1.55 (1.22–1.97) for light current, and 1.43 (1.17–1.76) for heavy current smokers. Using urine cotinine (never smokers as referent), the corresponding adjusted HRs (95% CI) were 1.04 (0.74–1.45), 1.32 (1.06–1.64), and 1.62 (1.34–1.95). Light and heavy current smoking, as assessed by self-reports and urine cotinine, are each associated with an increased risk of hypertension.</p>