Abstract. Within the Decay Data Evaluation Project (DDEP) an updated comprehensive assessment has been made of the decay characteristics of 133 Ba, 140 Ba, 140 La, and 141 Ce. Experimental data published up to 2016 along with other information (new compilations, analyses and corrections) were taken into account. Newly evaluated values of the half-lives and a number of other key decay characteristics are presented in this paper for all four radionuclides.