Provided is a method of forming a pattern and an actinic-ray- or radiation-sensitive resin composition that excels in the limiting resolving power, roughness characteristics, exposure latitude (EL) and bridge defect performance. The method of forming a pattern includes (1) forming an actinic-ray- or radiation-sensitive resin composition into a film, (2) exposing the film to light, and (3) developing the exposed film with a developer containing an organic solvent. The actinic-ray- or radiation-sensitive resin composition contains (A) a resin containing a repeating unit with a structural moiety that is configured to decompose when exposed to actinic rays or radiation to thereby generate an acid, and (B) a solvent.