BACKGROUND: Depression is frequently characterized by patterns of inflexible, maladaptive, and ruminative thinking styles, which are thought to result from a combination of decreased attentional control, decreased executive functioning, and increased negative affect. Cognitive Control Training (CCT) uses computer-based behavioral exercises with the aim of strengthening cognitive and emotional functions. A previous study found that severely depressed participants who received CCT exhibited reduced negative affect and rumination as well as improved concentration. AIMS: The present study aimed to extend this line of research by employing a more stringent control group and testing the efficacy of three sessions of CCT over a 2-week period in a community population with depressed mood. METHOD: Forty-eight participants with high Beck Depression Inventory (BDI-II) scores were randomized to CCT or a comparison condition (Peripheral Vision Training; PVT). RESULTS: Significant large effect sizes favoring CCT over PVT were found on the BDI-II (d = 0.73, p <.05) indicating CCT was effective in reducing negative mood. Additionally, correlations showed significant relationships between CCT performance (indicating ability to focus attention on CCT) and state affect ratings. CONCLUSIONS: Our results suggest that CCT is effective in altering depressed mood, although it may be specific to select mood dimensions.