The present study evaluated: (1) the effects of two training programs designed for promoting Theory of Mind (ToM) skills in children aged 7/8; and (2) the relations between second-order recursive thinking (II-order-RT), advanced-ToM (Adv_ToM) and metacognition. Ninety-one 7- to 8-year-old children were assigned to one of three training conditions: a II-order-RT, an Adv_ToM, and a control condition. Groups were equivalent at pretest for SES, executive functions and reading comprehension. The main effect of time was significant on II-order-RT, but not on Adv_ToM and metacognition. Children of the II-order-RT group improved their performance on over the training period II-order-RT while children of the control group did not) and they also outperformed children of the control condition at posttest. This positive effect generalized to Adv_ToM. Children of the Adv_ToM group improved over the training period their performance on both Adv_ToM and II-order-RT (while children of the control group did not); moreover, they outperformed children of the control condition at posttest on Adv_ToM, but not on II-order-RT. The benefits of both ToM training programs extended to metacognitive knowledge. Our findings throw light upon generative mechanisms of acquisition that explain the relation between II-order-RT and Adv_ToM, and between these mature ToM skills and metacognition.