Ionising radiation induces complex molecular responses in human cells resulting in changes at mRNA and protein expression. Limited data is available on the transcriptional status of functional genes in response to ionising radiation using peripheral blood mononuclear cells (PBMCs). In the present study, transcriptional profiles of Histone 2B, CTP synthase and PLK3 were studied. Blood samples were collected from ten random healthy males with informed consent. Whole blood irradiation was done at four different dose groups (0.3, 0.6, 1.0 and 2.0 Gy) at a dose rate of 0.68 Gy/minute. PBMCs were separated immediately as well as 4 hours post-irradiation. Total RNA was isolated, transcribed to cDNA and real-time quantitative PCR was performed. Our results revealed a dose-dependent significant upregulation at H2B and CTP synthase at 4 hours post-irradiation. At PLK3 significant upregulation was observed at 2.0 Gy (P = 0.007). In conclusion, these genes can be used for population monitoring programme.