Background: The association of blood pressure (BP) with prostate cancer risk after accounting for asymptomatic prostate-specific antigen (PSA) testing, and with prostate cancer death, is unclear. Methods: We investigated BP, measured at a mean age of 38 years amongst 430,472 men from five Swedish cohorts, in association with incident prostate cancer (n=32,720) and prostate cancer death (n=6718). Hazard ratios (HRs) were calculated from multivariable Cox regression models. Results: Increasing systolic and diastolic BP levels combined were associated with a slightly lower prostate cancer risk, with a HR of 0.98 (95% confidence interval, 0.97-0.99) per standard deviation (SD) of mid-BP (average of systolic and diastolic BP). The association was restricted to the PSA era (1997 onwards, HR 0.96 [0.95-0.98]), to diagnoses initiated by a PSA test in asymptomatic men (HR 0.95 [0.93-0.97]), and to low-risk prostate cancer (HR 0.95 [0.92-0.97]). There was no clear association with more advanced disease at diagnosis. In cases, a slightly higher risk of prostate cancer death was observed for higher BP levels, HR 1.05 (1.01-1.08) per SD of mid-BP; however, the association was restricted to distant metastatic disease (P for heterogeneity between case groups=0.01), and there was no association for BP measured less than 10 years prior to diagnosis. Conclusions: Prediagnostic BP is unlikely an important risk factor for prostate cancer development and death. Less asymptomatic PSA testing amongst men with higher BP levels may explain their lower risk of prostate cancer. Impact: Elevated BP is unlikely to be an important risk factor for prostate cancer.