PRRSV-PDA is an integrated database and tool for exploring the worldwide genetic diversity and phylogenetic relationship of porcine reproductive and respiratory syndrome virus (PRRSV). It mainly consists of data statistics module and three data analysis modules. The data statistics module displays the distribution of frequency of PRRSV sequences in the database based on genotype, host, sequence type, origin, and publication status. The first analysis module, “Search”, is used for sequence comparison between query and database sequences to determine their similarity level and to identify the novel sequence not present in the database. The “Phylogenetic placement” module focuses on the investigation of phylogenetic relationship between query and known sequences in the database by locating the query on the reference phylogenetic tree. By considering geographic distribution of sequences found in each country/continent, the “Phylogeography” module will illustrate the pre-analyzed phylogeographic result, providing insights into how genetic diversity in PRRSV was generated and distributed across the regions. PRRSV-PDA can be useful for researchers, veterinarians, pig industry, disease control and prevention agency for studying the evolution and genetic diversity of PRRSV and for monitoring the genetic change and geographic distribution of PRRSV.