zIsothermal convective mass transfer behaviour of a horizontal rotating circular cylinder exposed to a two dimensional slot jet of air was determined as a function of the flow and the geometrical parameters using a photo-evaporative mass transfer measurement technique. The rotational Reynolds number (Re-w) varied from 0-8.0 x 10(4), the jet exit Reynolds number (Re,) from 4.6 x 10(4)-2.70 x 10(5), the ratio of the cylinder diameter to the jet slot height (d/D) from 3.333-15, the ratio of the distance between the jet exit and the front of the cylinder to the slot height (L/D) from 1-16, the ratio of the off-set between the axis of the cylinder and the symmetry plane of the jet to the slot height (E/D) from -0.555-2. 133 and the jet impingement angle (phi) from 20 degrees-90 degrees. Some correlations of the mean Sherwood number (Sh) have been produced by using the experimental data. Comparison of the mass transfer performance of the present configuration with those of a stationary cylinder in the same jet flow and in a uniform crossflow of the similar velocities indicated that the rotation had a deleterious effect on the mean mass transfer.