With the aim to investigate whether the prevalence of blood pressure (BP) control in the elderly changes over time and according to the presence of comorbidities, as much as 123 elderly hypertensive outpatients were selected and followed for at least one year and within four years from their enrollment. BP control was considered to be achieved when BP was < 140/90 mmHg (< 130/80 mmHg for patients with type 2 diabetes mellitus and/or chronic kidney disease). Estimates of prevalence of BP control (PBPC) over follow-up time were derived using generalized random-effects pattern-mixture models for longitudinal studies. At four years of follow-up the estimated PBPC increased from 58.5% (baseline) to 85.5% (p for trend=0.010), and was lower in patients with type 2 diabetes mellitus and/or chronic kidney disease (from 38.2% to 68.3%, p for trend=0.062) than in patients with other comorbidities (from 76.4% to 94.5%, p for trend=0.020). Compliancy with the doctor plays a key role for BP control, even for patients with comorbidities.