The quality of life has become an indispensable element in the evaluation of treatments, especially as clinical trials are generally conducted in more than one country. In cancerology, numerous questionnaires have been developed and validated, but most of them are in English. This article presents the stages of translation and validation of the French version of the FLIC (Functional Living Index – Cancer). It applies to a sample of 200 patients, 47% of whom have breast cancer. The acceptability of this questionnaire is good (92.2%). The main psychometric criteria were verified. The Cronbach alpha coefficient, equal to 0.90, shows good reliability. A factor analysis was conducted to examine construct validity; it revealed a 5-factor solution accounting for 62% of the variance. These 5 factors are associated with specific domains: physical, psychological and social functioning, current well-being and disease symptoms. The global scores of the FLIC correlate significantly with those of the different scales of the EORTC QLQ-C30. Moreover, clinical relevance is ensured by its correlation with certain clinical variables (WHO index, location of tumour). The French version of the FLIC can be used to measure the quality of life of patients afflicted with cancer, but further studies are necessary to confirm its reliability.