Medical doctors found out that in comparison to adults the number of children with airways desease due to air pollution is much higher. However up to now experimentally data for total deposition of aerosol particles in the human respiratory tract are predominantly published for adults. In the present study 29 children with normal lung function data volunteered for the determination of total deposition using an inline inhalation technique. It turns out that total deposition data for children are higher than for adults, and thus confirm a general tendency already reported by BECQUEMIN et al. (1986). Using the inline technique the differences in deposition values between children and adults are more pronounced than found by those authors.