Indications for noninvasive positive pressure ventilation (NPPV) have been expanding since the 1990s. The efficacy of NPPV has been established in the treatment of cardiogenic pulmonary edema and exacerbation of chronic obstructive pulmonary disease. Accumulating evidence has also suggested its potential usefulness in other contexts associated with respiratory insufficiency. Meanwhile, large areas remain in which the benefits of NPPV are not uniform or yet to be determined. Therefore NPPV should be regarded as a complementary method to invasive ventilation, and care must be taken in its application to assess its potential harm and benefits based on current evidence and recommendations. It should also be emphasized that the success of and the actual indications for NPPV should substantially vary depending on the skill level of the medical care team, requiring a flexible and prudent implementation of NPPV, especially for conditions where its efficacy has not been determined.