Single-chain Monte Carlo simulations of amphiphilic diblock star copolymers were carried out in continuous space using implicit solvents. Two distinct architectures were studied: stars with the hydrophobic blocks attached to the core and stars with the polar blocks attached to the core, with all arms being of equal length. The ratio of the lengths of the hydrophobic block to the length of the polar block was varied from 0 to 1. Stars with 3, 6, 9 or 12 arms, each of length 10, 15, 25, 50, 75 and 100 Kuhn segments, were analyzed. Four distinct types of conformations were observed for these systems. These, apart from studying the snapshots from the simulations, have been quantitatively characterized in terms of the mean-squared radii of gyration, mean-squared distances of monomers from the center of mass, asphericity indices, and static scattering form factors in the Kratky representation as well as the intrachain monomer-monomer radial distribution functions. (C) 2003 American Institute of Physics.