Background: The European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 is a core questionnaire designed to evaluate health-related quality of life (HRQoL) of cancer patients participating in international clinical trials. It is available in several languages including Danish. The EORTC QLQ-TC26 is a supplemental module developed for patients with testicular cancer, which can be useful in clinical trials. Despite Denmark holding a high prevalence and incidence of testicular cancer, no Danish translation was previously available. This paper describes the translation process and pilot testing of the Danish translation of QLQ-TC26. Methods: The English language EORTC QLQ-TC26 was translated into Danish using forward and backward procedures with reconciliation. The translated instrument was assessed in semi structured cognitive interviews in a sample of 10 patients ages 20-56 receiving treatment for testicular cancer. Results: In one round of pilot testing, no changes were required for the Danish translation based upon patient comments. The Danish translation was agreed by participants to be both culturally acceptable and semantically comprehensible. Conclusions: The pilot testing of the Danish translation of the EORTC QLQ-TC26 was performed in one round of patient interviews; these results support the Danish translation as a comparable instrument to the English language version. However, further validation is required to ensure complete equivalency. These results support the use of the EORTC QLQ-TC26 in future clinical trials conducted with Danish-speaking patients.