The purpose of this study was twofold: first, to answer the question of which abilities, from a selected set of 12 abilities from the structure-of-intellect model of Guilford, were related to achievement in Physical Science Study Committee (PSSC) physics, and, second, to determine how the physics achievement prediction properties of these structure-of -intellect factors compared with those of a state-wide test. One hundred and nineteen seniors enrolled in PSSC physics at three high schools in Florida were administered tests representing the factors. Multiple stepwise regression analyses were performed to identify which specific factors were most closely related to physics achievement as measured by a PSSC unit test. Similar analyses were performed with scores on the Florida State-Wide Twelfth Grade Test being used to predict physics test scores. Among the results, patterns of structure-of-intellect factors were found related to PSSC physics achievement, although dependent on sex. In comparing PSSC achievement prediction with predictions from the Florida State Test, the structure-of-intellect factors gave significantly greater multiple R values. (Author/CP)