An aerosol composition comprising a propellant and a first particulate material comprising particles having a median aerodynamic diameter with the range 0.05 to 11 .mu.m, such as a medicament suitable for pulmonary inhalation, and a second particulate material comprising particles having a median volume diameter within the range 15 to 200 .mu.m. The presence of the second particulate material provides good suspension properties, particularly where the propellant is a hydrofluoro alkane.