The factor structure of Form Y of the State-Trait Anxiety Inventory (STAI-Y) was examined with 1,862 Japanese adult workers (1,509 men, 353 women). The initial principal component analysis extracted three factors based on the scree test. All 20 state (S-Anxiety) and 20 trait (T-Anxiety) items had dominant salient loadings on the first factor, which reflected "over-all anxiety." The three factors identified by an oblique (promax) rotation were labeled "anxiety-absent," "state anxiety-present," and "trait anxiety-present." All 20 items with dominant salient loadings on the first oblique factor were clearly grouped on the basis of their content, indicating the absence of anxiety. The second and third oblique factors, defined almost entirely by the STAI-Y anxiety-present items, clearly reflected the state-trait distinction in this sample of Japanese workers.