Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation technique that modifies cortical excitability in a polarity-dependent way that has been increasingly investigated for the treatment of major depression (MD) during recent years. Stimulation for few minutes can induce plastic alterations of cortical excitability and improve cognitive performance. Even if the available evidence, including randomized clinical trials, has generally reported encouraging results in treatment of major depression and treatment-resistant depression, the use of tDCS in mood disorders should still be considered experimental. In fact, further research is needed to better define the optimal stimulation parameters, duration of treatment, durability of clinical effect and predictors of response. Nevertheless, to date, tDCS has shown a favourable tolerability profile, is easy to apply, portable and inexpensive. Taken together, increased use of the technique in the treatment of depressive disorders may be expected in the near future.