Background A minimum of six electroconvulsive therapy (ECT) treatments has to be delivered to achieve sustained improvement in major depression. However, the mechanisms of the therapeutic actions of ECT are still debated. Objective We aimed to study the time course and duration of increased K v7.2 and K v11.1 mRNA expression in the hippocampus and piriform cortex (Pir) after electroconvulsive stimulation (ECS). Methods Adult male Sprague-Dawley rats received three ECS per week over 1, 2, or 3 weeks and were decapitated 3 days after the last stimulus. Additional groups of rats receiving nine ECS were sacrificed 7 or 28 days after the last ECS. In situ hybridization was used to measure K v channel mRNA expression after ECS. Results K v7.2 mRNA was increased in the hippocampus and Pir 3 days after both six and nine, but not after three ECS. This was also seen for K v11.1 mRNA in Pir. These changes lasted for at least 7 days. Conclusions These results indicate that the changes in K v7.2 and K v11.1 channels may contribute to the therapeutic effect of ECT. However, further research needs to be undertaken in this area to extend these findings.