Background The present study aimed at analyzing whether training in emotional competences (EC) would increase the level of perceived EC among unemployed adults, whether the unemployment duration would moderate the effects of the training and whether the changes in EC would predict changes in the levels of perceived stress, somatic complaints, mental health, and mood states. Methods Seventy‐five participants were randomly allocated to an EC training program, or a control group. Following a controlled experimental design, the participants completed all the measures prior to the intervention (T1), one month later (T2) and six months after the first data collection (T3). Results The results showed that change in EC after the training depended on the duration of unemployment. The difference between the experimental and control groups in EC after the training was significant when the participants had been unemployed for less time. In addition, the results indicated that changes in EC were found to be significant predictors of changes in perceived stress, mental health, somatic complaints, and vigor and confusion (mood dimensions) six months after the intervention. Conclusion The data suggest that unemployment duration plays a crucial role in determining the range and intensity of intervention effects.