The Kuju volcanic group, located in central Kyushu, Japan, consists of small stratovolcanoes and lava domes. To refine the eruptive history of the group, we conducted accelerator mass spectrometry (AMS) radiocarbon dating of charcoal fragments from three pyroclastic-flow (PF) deposits on the southern slope. The obtained 14C dates are consistent with the geomorphology, stratigraphy, and thermoluminescence (TL) ages. The Handa PF deposits, which are products of the largest eruption of the group, were dated to ~53.5 ka BP. The Shirani and Muro PF deposits, which are block-and-ash flows, were dated to 44 to >50 cal ka BP and 35–39 cal ka BP, respectively. These ages can be correlated with TL ages for lava domes. This study demonstrates that the lava domes and associated PF deposits formed after the Handa eruption.