AbstractThe regional component (∆R) of the marine reservoir effect (MRE), which is crucial for the accurate calibration of radiocarbon ages of marine-influenced samples, was determined for the Cuban northwestern coast. Fifteen different locations were studied by¹⁴C dating of pre-bomb known-age marine shells specimens of bivalves and gastropods from the Felipe Poey Museum collection. Accelerator mass spectrometry (AMS)¹⁴C measurements were performed at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) and mean ΔR values were estimated. The distribution of results indicates ∆R values from −46±38 to 140±52¹⁴C yr and a possible pattern related to the position along the coast and ocean dynamics. We present both mean values for each region and a general ∆R of 28±13¹⁴C yr for the northwestern coast of Cuba.