African swine fever (ASF) is a fatal disease in swine. Concentration of cases over summer and outbreaks in farms with high levels of biosecurity might support the hypothesis of ASF virus transmission via insects. A total of 28,718 insects were collected from 14 pig farms affected by ASF in the Republic of Korea. The insects collected were flies (N = 27,310, 95.1%), mosquitoes (N = 1,198, 4.2%), and cockroaches (N = 24, 0.1%). The remaining 0.6% (N = 186) could not be taxonomically classified. All the insects collected showed no trace of ASF Virus-DNA was detected by laboratory analysis. It is premature to conclude on the role of insects in the transmission of ASFV. However, the possibility of the virus spreading via insects should not be overlooked.