This research note investigates the relationship between output and unemployment in Greece at a regional level through the implementation of Okuns's law. Current practice is primarily restricted to the national level, and thus ignores the regional dimension of this relationship. To this end, we apply modern unit root test and cointegration techniques based on panel data settings. Using panel data is necessary because typical spans of economic time series are short, so the entire panel must be exploited in order to draw sharper inferences. The empirical results reveal that Okun's law can be confirmed for six out of the 13 regions we examine.