Asymmetric rotating disc contactor (ARDC) offers potential advantages in having comparable mass transfer coefficient (k(C)g) and lower back mixing over the conventional rotating disc contactor (RDC). In the present work, measurements of dispersed phase hold-up (is an element of(D)), effective interfacial area (g), continuous phase mass transfer coefficient (k(C)g) and axial dispersion coefficient for the dispersed as well as continuous phase have been performed in 80 mm and 150 mm i.d. ARDC over a wide range of operating variables and physical properties. From these measurements, the values of slip velocity and sauter mean drop diameter (613,2) have been estimated. Suitable correlations have been proposed for is an element of(D), V-S, k(C)g, g, k(C), d(3,2), Pe(C) and Pe(D). The results on true mass transfer coefficient (k(C)) have been compared with those published in the literature. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.