Recently the lateral (2-D) profiling of B ions implanted into crystalline Si has been measured using various tomography techniques. By the aid of Monte Carlo simulations the 3-D distribution is examined for the case of 80 keV B ions implanted into (100) Si. We present an asymmetric function expressing the lateral straggling versus depth. This is an exponential function whose component is a third order polynomial. The parameters involved bear the dependence of the incident angle on the 2-D profiles, including the cases of aligned and random incidence.