A recording condition determining method is executed by a recording device performing recording by a main scanning (P1, P2, P3, P4), in which while moving a recording head (15) in a main scanning direction (D1, D2), dots are ejected from nozzles (17) onto a recording medium (30), and a sub scanning, in which the recording medium is transported in a sub scanning direction (D3). The method includes a patch recording step of recording patches (45) onto the recording medium by the overlap-processing in which the main scanning is performed on a partial region of the recording medium in an overlapping manner a plurality of times, the patch recording step including recording the patches at a plurality of different positions in the main scanning direction by a plurality of types of the overlap-processing under respectively different recording conditions. The method further includes a selection accepting step of accepting selection of a patch from among a plurality of the recorded patches, and a determination step of determining, as the recording condition of the overlap-processing of an actual recording, the recording condition of the overlap-processing associated with the patch selected in the selection accepting step.