Cui died on 13 March 1918 from cerebral apoplexy and was buried next to his wife Mal'vina (who had died in 1899) at the Smolensk Lutheran Cemetery in Saint Petersburg.
Cui faleceu o 13 de marzo de 1918 dunha apoplexía cerebral e foi enterrado xunto á súa dona Mal'vina (que morrera en 1899) no cemiterio luterano Smolensk de San Petersburgo.