A pressurized aerosol dispenser comprising a container (2) for material to be stored therein and dispensed therefrom, and a metering dispensing valve (1), said metering dispensing valve (1) comprising a generally cup-shaped metering vessel (7) held in place by means of a cap (3) fixedly mounted upon said container (2), and a sealing member (9) disposed between the metering vessel (7) and the cap (3), said sealing member (9) having an opening within which a valve stem (8) is mounted for sliding movement along a longitudinal axis, the metering vessel (7) having an open mouth, an internal surface of which defines an annular contact surface (24, 25) against which said sealing member (9) bears, wherein said contact surface (24, 25) comprises a first outwardly-flared portion (24) disposed at a first angle to said longitudinal axis and a second outwardly-flared portion (25) disposed at a second angle to said longitudinal axis, said second angle being greater than said first angle such that an annular ridge (26) is formed.