The manuscript provides a comprehensive review of the results that have been obtained from radon concentrations in the ground, particularly their correlation with earthquakes, over the past fifty years in Greece. Data collection methods have evolved from solid-state nuclear track detectors to more advanced continuous monitoring devices. The influence of meteorological parameters was eliminated through time series analysis, revealing correlations between radon signals and earthquakes M3.5–6.5. Anomalies persisted for days to weeks, depending on the faulting type. The review concludes with a discussion and evaluation of the results, highlighting the potential for future research on this intriguing correlation between radon and earthquakes.