Objective To investigate the effects of noninvasive positive pressure ventilation (NPPV) on patients with acute left heart failure. Methods Twenty patients with acute left heart failure diagnosed between September 2013 and July 2014 were randomized into treatment group (n=10) and control group (n=10). Both groups used conventional sedations, diuretics and drugs that strengthened the heart and dilated the vessels, while early use of NPPV was applied in the experimental group. Arterial blood gas analysis [pH value, pressure of arterial carbon dioxide (PaCO2), and pressure of arterial oxygen (PaO2)], heart rate (HR), respiration, duration of Intensive Care Unit (ICU) stay and invasive mechanical ventilation, duration of overall mechanical ventilation, and success case numbers before and two hours after treatment were observed and analyzed. Results For the control group, two hours after treatment, PaO2 was (67.0±8.5) mm Hg (1 mm Hg=0.133 kPa), HR was (124±10) times/min, Respiration was (34±4) times/min, the duration of ICU stay was (6.0±1.1) days, invasive ventilation was for (32.0±3.1) hours, and the total time of mechanical ventilation was (32.0±3.1) hours. Those indexes for the treatment group two hours after treatment were: PaO2, (82.3±8.9) mm Hg; HR, (98±11) times/min; respiration, (24±4) times/min; the duration of ICU stay, (4.0±0.8) days; invasive ventilation time, (16.0±1.3) hours; the total time of mechanical ventilation, (26.0±1.8) hours. All the differences for each index between the two groups were statistically significant (P < 0.05). Conclusion Early application of NPPV can rapidly relieve clinical symptoms and reduce the medical cost for patients with acute left heart failure.