Twenty-nine third-and fourth-grade teachers and m,enty-five fifth-and sixth-grade teachers from the Texarkana (Arkansas and Texas) area pubfic schools were trained using the Full Option Science System (FOSS). Participants were given pretests and posttests to measure their: confidence toward teaching science, science content lmowledge, attitude toward teaching science, and attitude toward science. Pretest and posttest results were compared using a paired t-test. The results revealed sigT#ficant gains for both groups in teacher confidence toward teaching science, science content knowledge, and attitude toward teaching science. No sigmficant increase in attitude toward science was detected in the third-and fourth-grade teachers. However, the fzfth-and sixth-grade teachers did show a significant increase in their attitude toward 17 science. Overall, it appears that Full Option Science System training is effective for third-through sixthgT"ade teachers.