Numerical simulations of the mass-transfer of droplet in a continuous phase were done for a conjugate problem. The effect of free and combined convection on the mass transfer was investigated by solving the governing equations using the finite element method. The results show that the mass transfer depends very strongly on the flow conditions. The effect of free convection on mass transfer at high Reynolds number is small. The mass transfer by the combined free and forced convection for a rising drop was found to be smaller than that for a falling drop. The simulation was limited to Re-c less than or equal to 20. less than or equal to 2002 Elsevier Science Ltd. All rights reserved.