The purpose of the present study was to compare pharyngeal and polysomnographical findings during drug-induced sleep endoscopy (DISE) performed with either propofol or midazolam as a single sedative agent. It is prospective, non-randomized, double-blinded case series study. Sixteen patients with sleep disordered breathing were sedated first with propofol and after full wake up with midazolam. Simultaneous polysomnography (PSG) was performed. We compared the zones of obstruction and vibration found with both drugs using the VOTE classification. Simultaneous PSG findings are also compared. There were 15 men and one woman; the mean age was 42.7 years old, mean body mass index 26.9 kg/m(2). Average DISE duration was 20 min with Propofol and 14.3 min with Midazolam. The induced sleep stage obtained was N2 with both drugs. Outpatient physical exam did not correlate with drug-induced sleep findings. There was a good correlation between DISE results with both drugs in all the areas of collapse except the velum (p < 0.005). Using a continuous perfusion, there is a good agreement in the findings observed in DISE performed with propofol and midazolam and PSG.