The increased use of nuclear technology for energy and defence purposes has inadvertently increased the risk of radiological accidents or nuclear terrorist attack. A reliable and precise system must be in place for efficient triage management immediately after such an event. In addition to the conventional biodosimetric biomarkers like dicentric chromosome and micronucleus analysis in human peripheral blood lymphocytes, the present interest is to develop a modified γ-H2AX foci analysis as a potential biomarker. The project also aims to address the problem of signal loss by inhibiting the dephosphorylation of γ-H2AX foci. Furthermore, efforts are also made for the rapid analysis of foci by automation of microscopic image analysis and also with the alternative flowcytometric methods. The investigations on the metabolic and serum biomarkers for their potential to be used in dosimetry are also underway.