Alcohol-dependent patients show attentional and approach biases for alcohol-related stimuli. Computerized cognitive bias modification (CBM) programs aim to retrain these biases and reduce relapse rates as add-ons to treatment. Retraining of alcohol-approach tendencies has already yielded significant reductions of relapse rates in previous studies, and retraining of biased attention toward alcohol is promising approach. The current large-scale randomized controlled trial compared the clinical effects of these training methods-separately and in combination-to those of sham training methods and a no-training control, as an add-on to regular treatment.Participants were 1,405 alcohol-dependent patients of an inpatient rehabilitation clinic. In addition to regular treatment, patients were randomized to receive 6 sessions of approach-bias retraining, 6 sessions of attention-bias retraining, 3 sessions of each of these CBM training varieties, 6 sessions of variants of sham training, or no training. Effects of the training methods were evaluated by measuring treatment success at 1-year follow-up.Primary outcome: The 3 active training conditions yielded higher success rates at 1-year follow-up than sham training or no training (8.4%, on average). Secondary results (available for half of the sample): Both varieties of CBM had only small effects on the targeted biases (significant only for the combined training). Moreover, neither significant mediation of the clinical effect by the change in trained bias nor significant moderation of the clinical effect was found.Both alcohol-avoidance training and alcohol-attention training increased success rates effectively, as did the combination of both methods. Future studies should test ways to increase training effectiveness further. (PsycINFO Database Record (c) 2018 APA, all rights reserved).