The rise velocity of tube-draining bubbles in Newtonian and non-Newtonian fluids has been studied for vertical and inclined tubes. The experimental data are described in terms of the Froude (Fr) Eotvos (Eo), and Morton (M) numbers. The Froude number is given as a function of the angle of inclination (B) and Eo in order to represent the effect of tube size, inclination angle. and fluid properties on the rise velocity of the bubble. As the angle of inclination from the horizontal increases, Fr increases, reaches a maximum, and then decreases for all fluids. Thr maximum Fr value occurs at larger angles of inclination when the fluid is non-Newtonian. For Newtonian and non-Newtonian fluids possessing similar values of surface tension and zero-shear rate viscosity, the Fr values are similar for vertical tubes. However, the Fr values are generally lower for non-Newtonian fluids in inclined tubes under these same conditions.