The present invention is intended to provide a process for forming an electrodeposition coating film, wherein generation of gas pinhole is reduced and coating film appearance is excellent without using a specific resin as a binder resin.The present invention relates a process for forming an electrodeposition coating film having reduction of generation of gas pinhole, comprising a step of electrocoating by immersing an article to be coated in a cationic electrodeposition coating composition, wherein, the cationic electrodeposition coating composition comprises 10 to 30 parts by weight of a pigment comprising zinc oxide based on 100 parts by weight of a solid content of the coating composition, and the content of zinc oxide contained in the pigment is 0.25 to 5 parts by weight based on 100 parts by weight of the pigment.