One of the key features of gambling disorder (GD) is impairment in cognitive-emotional control. Considering the negative consequences of GD, the present study investigated the effectiveness of emotional working memory training (eWMT) in improving cognitive control, attention, working memory capacity, and cognitive emotion regulation strategies (CERS) among young adults with GD compared to a placebo group. Following the initial assessment in the pre-test phase, eligible participants were randomly assigned to one of two groups: experimental (n = 34) and placebo (n = 30). These groups completed eWMT and a feature matching task for 20 sessions respectively. The post-test and follow-up measures indicated that eWMT significantly improved cognitive control, attention, working memory capacity, and the use of maladaptive cognitive emotion regulation strategies, but it had no significant effect on adaptive CERS. The promising results of the present study suggest the use of eWMT as a new intervention to improve cognitive-emotional control among individuals with online gambling problems.