OBJECTIVES: To compare health-state utility values obtained using three different instruments administered to patients with pulmonary arterial hypertension (PAH) enrolled in a randomized controlled trial of sildenafil. METHODS: Data for this study were obtained from a large phase III clinical trial in which patients were randomized to receive either sildenafil or placebo for 12 weeks.  At each visit (baseline, weeks 1, 4, 8, and 12 of follow-up), patients were administered the Short Form-36 General Health Survey (SF-36) and the EuroQol Health Survey (EQ-5D); additionally they also were asked to provide a direct assessment of their current health state using a visual analog scale (VAS).  Responses to the SF-36 and EQ-5D were then converted to health-state utility values using published algorithms.  Patients were pooled across treatment groups, and attention was focused on baseline values. Statistical significance of differences between these three estimates was ascertained using paired t tests. RESULTS: There were a total of 274 patients across both treatment groups in the intent-to-treat population.  Proportions of 0–30, 31–60, and 61–100 health-state utility values were 0.4%, 22.6%, and 77.0% for SF-36; 16.2%, 9.6%, and 74.3% for EQ-5D; and 8.6%, 47.2%, and 44.2% for VAS, respectively.  Mean (95% confidence intervals) health-state utility values were 71.4 (69.6–73.1) for SF-36 (P<0.01 vs EQ-5D or VAS), 63.2 (60.2–66.3) for EQ-5D (P<0.01 vs VAS), and 59.0 (56.9–61.2) for VAS, respectively. CONCLUSIONS: Ratings of current health by PAH patients are significantly worse with a single-item VAS scale than based on responses to the EQ-5D and SF-36 health questionnaires. The EQ-5D appears to yield somewhat lower values than the SF-36. Further research is needed to better understand the reason(s) for these differences.