Background In this study, the time and path of transmission of H1N1 serotype influenza A viruses in Iran and neighboring countries have been investigated by using Bayesian phylogeography analysis on the sequences extracted from the gene bank. Methods We obtained all hemagglutinin (HA) and neuraminidase (NA) nucleotide sequences of influenza H1N1 available up to December 25, 2020, from Iran and its neighboring countries (i.e., Pakistan, Afghanistan, Turkmenistan, Armenia, Azerbaijan, Turkey, and Iraq). We also performed a Bayesian Markov chain Monte Carlo method to infer the evolutionary dynamic and the most recent common ancestor for the HA and NA sequences. Results Based on the extracted sequences, the age of emergence of H1N1 influenza virus serotype was older in Iran compared to neighboring countries, and Tehran had a key role and epicenter of transmission to other cities within Iran. The mean time of the most recent common ancestor of H1N1 viruses was 1989 (95% HPD: 1980-1994) for HA and NA as well. Conclusions Along with ordinary measures like resource management, diagnostic approaches, and preparedness to fight against viruses that were in place, continuous monitoring, and screening of H1N1 serotype influenza virus in the country, especially by implementation of feasible, effective, and innovative measures at border line should be initiated and identified gaps and shortage that should be a priority for virus control. It is also important for countries to have a regional monitoring program in addition to internal monitoring programs, as well as to start a virus molecular care program.