The investigation of laminar convective mass transfer and friction factor was performed experimentally for the circular tubes with the diameter of 0.20 mm and the L/d values in the range of 100-500 for a Reynolds number range of 40-1400. The pressure drop experiments were conducted with distilled water, and the mass transfer experiments were carried out with an electrochemical solution by using the electrochemical limiting diffusion current technique. The friction factor results showed good agreement with the classical Poiseuille flow theory, while Sherwood numbers are smaller than those obtained by conventional correlations. (C) 2009 Elsevier Masson SAS. All rights reserved.