The first studies of treatment of bronchiolitis in infants and toddlers with inhalation of hypertonic saline showed that the treatment was beneficial but later studies have challenged these results. Here, we review four systematic reviews from 2015-2017 and two more recent studies not included in the reviews. Our conclusions are that in moderately severe bronchiolitis, the benefits of treatment are small or absent and inhalations should not be routine. In severe cases, inhalation of hypertonic saline may be considered but benefits are not proven. Water is an irritant to the lower respiratory tract and saline is therefore doubtful as a placebo. We found only one study with conservative placebo (no inhalation). It showed no benefit of hypertonic NaCl and should be repeated.