BACKGROUND To investigate the expression and clinical significance of tissue inhibitor of metalloproteinases-1 (TIMP-1) and a disintegrin and metalloproteinase with thrombospondin type 1 motif 1 (ADAMTS1) in post-kidney-transplant bladder tumors. MATERIAL AND METHODS A total of 27 patients with new bladder tumors occurring after surgical kidney transplants (the experimental group) and 56 patients with conventional new bladder tumors (the control group) were included in this study. All the patients were confirmed to have transitional cell carcinomas by postoperative pathological examination. Fifteen pairs of new bladder tumor specimens (from each of the 2 groups) were selected and subjected to whole-genome oligonucleotide microarray screening to determine the differences in gene expression profiles and analysis using the biomolecule annotation system. Subsequently, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry, and Western blot analysis were performed to determine and compare differences in the expression of TIMP-l and ADAMTS1 in the urothelial tumors of the 2 groups. RESULTS Analysis of co-differentially expressed genes showed 23 groups of pathways with significant differences (P<0.05) and included immunosuppression and tumor development and progression. TIMP-l expression was significantly higher in the experimental group than in the control group, whereas ADAMTS1 expression was significantly lower in the experimental group than in the control group (P<0.05). CONCLUSIONS Significant differences in gene expression profiles were observed between patients with post-kidney transplant bladder tumors and those with conventional bladder tumors, and the expression of TIMP-1 and ADAMTS1 has important significance for the diagnosis of post-kidney-transplant bladder tumors.