Light scattering patterns have been calculated for a simple optical model constructed for single smooth and nonsmooth lymphocytes of healthy and infected individuals. It has been shown that the smooth and nonsmooth cells can be resolved using the intensities of the sideward and backward scattered light. We have found by calculations and validated by the flow-cytometer experiments that intensity distributions for the cells of lymphocyte populations can be used as a preliminary signatures of some virus infections. Potential biomedical applications of the findings for label-free flowcytometry detecting of individuals infected with viruses of hepatitises B or C and some others viruses are presented.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.