This study aims to investigate the association between ERCC1 codon C118T polymorphism and the response rate of platinum-based chemotherapy in patients with late-stage bladder cancer. A total of 41 eligible patients histologically confirmed as having stage IV muscle-invasive transitional cell carcinoma of the bladder were treated with platinum-based chemotherapy for 2-6 cycles. The genotypes of patients were determined by PCR amplification of genomic DNA followed by restriction enzyme digestion. Positive responses were categorized as complete and partial responses. In addition, progression-free survival (PFS) and overall survival (OS) were also determined as indicators of long-term outcomes. The genotype frequencies of C/C, C/T and T/T genotypes were 56.1, 34.1, and 9.8%, respectively. Positive response was observed in 14 patients (34.1%), while 27 patients (65.9%) were negative responders. As compared with individuals carrying the C/T and T/T genotypes, those with the C/C genotype had significantly improved short-term treatment responses (P = 0.018). The median PFS of patients carrying the C/C genotype was 6.3 months, while that of patients with C/T and T/T genotypes was 4.2 months (P = 0.023). Moreover, the median OS for patients carrying the C/C genotype was also longer as compared with that of patients carrying C/T and T/T (11.7 months vs 8.5 months, P = 0.040). Our results indicated that the ERCC1 codon 118 polymorphism may have predictive potential for chemotherapy treatment responses in late-stage bladder cancer patients.