A survey on the presence of the viruses of two economically significant diseases, white spot syndrome virus (WSSV) and monodon baculovirus (MBV) in wild-collected Penaeus monodon broodstock, was conducted during different seasons of the year in two major coastal areas of southeast India. The broodstock were collected along the coast of Tamil Nadu and Andhra Pradesh during summer, premonsoon, monsoon and post-monsoon seasons for three consecutive years. A total of 7905 samples were collected and subjected to MBV screening, and 6709 samples that were screened as MBV negative were diagnosed for WSSV. MBV was detected using rapid malachite green staining and WSSV by nested polymerase chain reaction. Prevalence data of the viruses were analysed using the EpiCalc 2000 program at 95% confidence interval. Samples collected from the Andhra Pradesh coast displayed a slightly higher prevalence of WSSV and MBV infection than those collected from Tamil Nadu, although this difference was not statistically significant (P > 005). In addition, it was found that the prevalence of both WSSV and MBV infections fluctuated according to season. Data on prevalence of these viruses in broodstock would be useful to develop strategies for shrimp health management along the southeast coast of India.