In order to understand the character of Epstein-Barr virus (EBV)-associated gastric carcinoma with lymphoid stroma (GCLS), we examined cell proliferation and death in comparison with gastric carcinoma without prominent lymphoid stroma (conventional gastric carcinoma). The EBV-encoded small RNA I (EBER-I) and apoptotic cells were examined by in situ hybridization (ISH) and by terminal deoxynucleotidyl tramferare (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL), respedvely, on formalin-fmed paraffin-embedded surgical speci-mens from 22 GCLSs and 23 conventional gastric carcinomas. lmmunostaining was performed for the detection of Ki-67 antigen (Ki-67), P53 protein (P53) and bcl-2 oncoprotein (BCL-2). The percentages of apoptotic and Ki-67-positive cells were expressed as apoptotic indices (Al) and Ki-67 labeling indices (KI), respectively. EBER- I was detected in I9 (86%) GCLSs in contrast to none in conventional carcinomas. Mean Al was 1.8 ± 0.6 in the EBER- I -positive GCLSs and 3.3 ± 1.7 in the conventional gastric carcinomas, the value being significantly lower in the former (p < 0.01). Mean KI was 40.0 ± 10.8 in the GCLSs and 48.5 ± 9.1 in the conventional gastric carcinomas, the value being significantly lower in the former (p < 0.05). P53 expression showed no significant difference between the 2 categories of carcinoma.