This report describes the development and validation of the Unisex ACT Interest Inventory (UNIACT). In contrast to other interest inventories in common use, the UNIACT contains scales on which males and females receive similar scores. In the development of the UNIACT, more than 200 potentially sex-balanced items were administered to 10,211 people, including 9th graders, 11th graders, college-bound students, college sophomores, and adults. The instrument resulting from the item tryouts consists of 90 items assigned to scales assessing the six Holland types and two underlying dimensions of work-related activity preferences--a data/ideas dimension and a things/people dimension. Scale distributions are highly similar for males and females, as evidenced by a median overlap of 92 percent. The goal was achieved with no loss in the technical quality of the instrument. The median coefficient alpha reliability estimates for the six scales assessing Holland types is .87. The scales intercorrelate according to theoretical expectations and exhibit the appropriate theory-based factor structure. Criterion-related validity data from a number of studies are summarized in the form of three-scale, high-point codes for 152 educational and vocational criterion groups. (Author/MV)