Aims: We evaluated risks associated with diaper changing in Finnish kindergartens where children were using either modern disposable paper or reusable cloth diapers. Methods and Results: We determined enteric micro‐organisms and ammonia in diaper‐changing rooms in four kindergartens in autumn and winter in the ambient air. No coliphages were detected in the air. The numbers of faecal coliforms and enterococci in air were typically low regardless of whether the children used either paper or cloth diapers. Ammonia concentrations increased over the background level because of diaper changing. Conclusions: The numbers of bacteria or coliphages are not expected to pose any high air hygiene risks, and increased ammonia air concentrations are unlikely to impair the health of staff or children when diapers are changed in modern kindergartens. However, increased ammonia gas concentrations indicate that some other diaper‐related gas‐phase emissions should be studied to understand better diaper‐related health risks. Significance and Impact of the Study: Modern reusable cloth baby diapers and the modern paper baby diapers used in this study are equally safe with respect to risks from airborne virus, bacteria or ammonia.