Cognitive effects of chess instruction on students at risk for academic failure was examined. Thirty-eight students, from three elementary schools, participated in this study. The experimental group received a ninety-minute chess lesson once per week over a three-month period; and the control group students regularly attended school activities after class. The experimental group performance on the test was not different from the control group performance. However, chess skill rating and TONI-3 posttest scores were significantly correlated when controlling for TONI-3 pretest score (d = 0.29). This suggests that chess skill rating is a key predictor for the improvement of student cognitive skills. Students at risk at beginning levels of competency in chess may be able to improve their cognitive skills and to improve their skill at chess. (Contains 4 tables.)