Inductive reasoning is a core cognitive process of fluid intelligence, predicting a variety of educational outcomes. The Cognitive Training for Children (CTC) program is an educational intervention designed to develop children's inductive reasoning skills, with previous investigations finding substantial effects of the program on both inductive reasoning ability and classroom learning. The present study assessed both individual and small-group CTC training against a no-treatment control condition to investigate the effects on inductive and deductive reasoning and mathematics achievement in a primary school-aged Australian cohort. Students who received individual training outperformed those in the control condition on measures of inductive and deductive reasoning, and those in the small-group condition also outperformed the control condition on a measure of inductive reasoning 3 months following training. However, hypotheses regarding transfer effects to mathematics achievement were not supported. Directions for future research, focusing on extended longitudinal studies and motivational variables, are discussed. (Contains 2 tables and 1 figure.)