--- - |2 Summary This study evaluated the efficacy of approach–avoidance training as an additional treatment for children and adolescents with obesity seeking inpatient treatment. Two hundred thirty‐two participants (8–16 years, 53.9% girls) were randomly assigned either to multisession approach–avoidance (IG) or to placebo training (CG). As outcomes, cognitive biases post intervention, body mass index, eating behaviour, food intake, self‐regulation, and weight‐related quality of life were assessed, also at 6‐ and 12‐month follow‐up. Modification of approach–avoidance bias was observed, but lacked in transfer over sessions and in generalization to attention and association bias. After 6 months, the IG reported less “problematic” food consumption, higher self‐regulation, and higher quality of life; effects did not persist until the 12‐month follow‐up; no significant interaction effects were observed regarding weight course. Despite there was no direct effect on weight course, approach–avoidance training seems to be associated with promising effects on important pillars for weight loss. Further research concerning clinical effectiveness is warranted. - European Eating Disorders Review, Volume 26, Issue 5, Page 472-482, September 2018.