An object of the invention is to provide a method for forming a multilayer coating film with excellent smoothness, distinctness of image, and water resistance, by a 3-coat 1-bake coating method, even when preheating after the application of an aqueous first colored coating composition is omitted. The present invention provides a method for forming a multilayer coating film, including (1) applying an aqueous colored coating composition (A) to a substrate to form a colored coating film; (2) applying an effect pigment-containing aqueous coating composition (B) containing a binder component (b1), an effect pigment (b2), and a hydrophobic solvent (b3) in proportions of 15 to 30 parts by mass of effect pigment (b2) and 25 to 60 parts by mass of hydrophobic solvent (b3) relative to 100 parts by mass of the binder component (b1), to the colored coating film, without preheating the colored coating film, to form an effect coating film having a film thickness of 7 to 13 micrometers when cured; (3) applying a clear coating composition (C) to the effect coating film to form a clear coating film; and (4) heating the three coating films formed in steps (1) to (3) to simultaneously cure these three coating films.