To assess the quality of life (QoL) of patients with cystic fibrosis (CF) followed at a university referral center for CF. A cross-sectional study involving application of the Cystic Fibrosis Questionnaire (CFQ) and Shwachman score in CF patients between April of 2008 and June of 2009. The sample consisted of 75 patients. The mean age was 12.5 ± 5.1 years (range, 6.1-26.4 years). The patients were divided into three groups by age in years: group I ( 14). The highest and lowest CFQ scores were for the nutrition domain in group III (89.3 ± 16.2) and the social domain in group II (59.5 ± 22.3), respectively. Groups I and III differed significantly regarding the treatment domain (p = 0.001). Regarding Shwachman scores, there were significant differences between patients scoring 70 in the social (group I; p = 0.045), respiratory (group II; p = 0.053), and digestive (p = 0.042) domains. In group III, severity did not correlate with QoL. In groups I and II, patients with an FEV1 < 80% of predicted did not differ from other patients for any CFQ domain. However, in group III, values for the following domains were significantly lower in patients with an FEV1 < 80%: physical (p = 0.012); body image (p = 0.031); respiratory (p = 0.023), emotional (p = 0.041); and social role (p = 0.024). It is important to assess QoL in CF patients, because it can improve treatment compliance.37184-9