We present the results of laboratory experiments investigating the dynamics of air bubbles rising in stagnant or co-flowing liquid (water) in inclined channels of rectangular crosssections. The experiments were conducted in a basic Plexiglas channel (1300 x 240 x 20 mm, in length (L), width (W), and height (H), respectively). Different channel geometries were obtained by insertion of suitably varied plates into the basic channel. Channel inclinations were ranging from alfa = 5̊ (almost horizontal) to 90̊ (vertical). Measurements and data analysis were carried out with the use of a high speed video camera system and image processing technique providing information on the bubble shape (bubble length LB and volume VB) and bubble rise velocity UB. The specific impact of channel geometry and inclination on the shape, stability, and velocity of rising bubbles was studied and discussed.\n