The scattering of He-Ne laser light by an average-sized human red blood cell (RBC) is investigated numerically. The RBC is modeled as an axisymmetric, low-contrast dielectric, biconcave disk. The interaction problem is treated numerically by means of a boundary-element methodology. The differential scattering cross sections (DSCS's) corresponding to various cell orientations are calculated. The numerical results obtained for the exact BBC geometry are compared with those corresponding to a scattering problem in which the cell is assumed to be either a volume-equivalent sphere or an oblate spheroid. A parametric study demonstrating the dependence of the DSCS on the wavelength of the incident wave and the cell's refractive index is presented. (C) 1999 Optical Society of America.