Tree-ring series from a single site and a single species were used as proxies to reconstruct past summer temperatures over 550 years in the Eastern Carpathian Mountains. The chronology was built using standard procedures in order to provide comparable information about this under-sampled region while preserving the low-frequency signals. The studied site offered abundant samples of both living trees and dead wood, which were carefully selected in order to minimize heterogeneity sources owing to a reduced availability of suitable material as e.g. in the Alps. The ring-width chronology spanned over 550 years with satisfying replication and showed an even segment length. The chronology correlated to temperature over quite a narrow window, temperatures of June and July only being significant. The reconstruction showed that the last 180 years was the warmest period with only three short episodes of anomalies. We present evidence that the summer temperatures in the Eastern Carpathian Mountains showed divergences as compared to the Alps and a clear regionality, the coolest period over the last 600 years occurring during 1720–1850.