The ejection anisotropy of Coulomb explosion fragments released from alkyl halide molecules (C2H5X, 1-C3H7X and 1-C4H9X, where X = Br, Cl) under strong 35 ps laser irradiation is studied by means of time-of-flight mass spectrometry. By comparing the angular distributions widths of the halogen fragment ions originating from multiply charged molecular ions it is concluded that the ejection anisotropy presents a weak dependence on the mass of the halogen atom, observed especially in the case of ethyl halide molecules, while a stronger dependence is found on the size of the alkyl chain. (c) 2008 Elsevier B. V. All rights reserved.