Gender-specific determinants of blood pressure (BP) values and control have not been the focus of clinical hypertension research. The purpose of this analysis was to identify gender-specific and multi-level (physician and patient) determinants of BP values and predictors of uncontrolled BP. We completed a subgroup analysis comparing men and women who participated in the Belgian PREVIEW study of second-line treatment effectiveness of valsartan, applying two-level hierarchical modelling of 90-day BP values and guideline-defined BP control. In total, 1665 women and 1525 men were treated by 504 general practitioners. Fewer women than men reached systolic BP (SBP) (P=0.015) and combined BP targets at 90 days (P=0.007). More than 26% of the variance in 90-day SBP (intra-class correlation coefficient (ICC)=0.270) and diastolic BP (DBP) (ICC=0.262) was attributable to physician-level factors for men; the physician-level ICCs for SBP and DBP were 0.259 and 0.268, respectively, for women. Determinants of 90-day BP values and predictors of uncontrolled BP varied considerably by gender. Many of the multi-level determinants of BP by gender are amenable to intervention, and the remainder can serve as warning signs to clinicians that patients may remain vulnerable to poor outcomes associated with sub-optimal BP control.