Background: No definite consensus has yet been reached on the best treatment strategy for the large group of infants hospitalised with bronchiolitis or pneumonia. Minimal handling is often recommended, although not evaluated scientifically. There is a need to evaluate the management, as the infants often are critically affected, and the costs for society are high. The aim of this RCT was to evaluate the most common physiotherapy intervention in Sweden for this patient group, including frequent changes in body position and stimulation of physical activity, compared to standard care.Methods: Infants 0–24 months old, without previous cardiac or respiratory diagnoses and born in gestational week 35+, were recruited in two Swedish hospitals. The participants (n=109) were randomised to either interventions in addition to standard care (intervention group) or to standard care alone (control group). The primary outcome measure was time to improvement. The secondary outcomes were immediate changes in oxygen saturation, heart rate and respiratory rate, time to improved general condition (parents’ assessment), and lung complications.Results: The median time to improvement was 6 hours in both groups (p=0.54). The result was similar when we adjusted for age in months, sex, tobacco smoke exposure, heredity for asthma/atopic disease, and early stage of the infection (for those with RSV), p=0.69. Analyses of the immediate changes showed no significant differences either (p=0.49-0.89). Time to improved general condition was median 3 hours in the intervention group and 6 hours in the control group, p=0.76. No lung complications occurred.Conclusions: No statistically significant differences in outcomes were detected between the intervention group and the control group. Both strategies were found to be equally effective and safe, indicating that the current recommendation of minimal handling for these infants should be reconsidered. Furthermore, the findings suggest that this treatment can be safely continued.