Primary human cervix cancers were implanted into athymic nude mice from 23 patient biopsy specimens. Tissue/tumor samples were implanted as chunks by trocar in different sites in irradiated (400 rad) or nonirradiated nude mice. Without irradiation 1 of 9 (11%) implanted tumors grew progressively and 13 of 26 (50%) implanted sites formed small implantation nodules that remained stable and usually regressed. In nude mice given 400-rad irradiation, 3 of 12 (25%) showed progressive tumor growth, 8 of 12 (67%) patient samples showed growth, and 24 of 36 (67%) implanted sites showed growth. Correlation with clinical data showed that the higher-stage and more malignant tumors were more likely to show progressive growth patterns, as was noted in three of five Stage III/IV cervix tumors grafted into 400-rad conditioned mice. Conversely, the lower-stage tumors were much less likely to show growth, and zero of nine samples with Stage I/II tumors showed progressive growth.