Background: The registering of eating habits requires a valid and reliable method. The purpose of this study is to validate the food intake frequency questionnaire, CDC-FFQ, which is an adaptation of another questionnaire, in order to assess the nutrition of the adult population of the Canary Islands. Methods: The CDC-FFQ questionnaire was given to 1,067 individuals taken from the general population (GP) and to 106 university students, aged 19 to 30. The second group was surveyed also in three 24-hour follow-ups. The nutrients were compared according to the CDC-FFQ in the GP and university students. The correlations were estimated between the CDCFFQ and the follow-ups for nutrients and groups of foods and the concordance of the intakes of nutrients and groups of foods in the extreme quintiles, for the university students. Results: The mean values between nutrients of the CDCFFQ between the GP, university students and the general population with university studies showed no significant differences except for vitamin B12 (p=0.004) and vitamin D (p=0.005). Correlations between the CDC-FFQ and the mean of the three follow-ups were obtained in the 0.202-0.601 range between nutrients adjusted by calories consumed in the case of the university students. By groups of foods, the correlations ranged between 0.243-0.542 for the CDC-FFQ and the followups. The concordance of nutrients ranged between 39% and 100% and for groups of foods, between 41% and 100%. Conclusions: The CDC-FFQ questionnaire is valid for classifying the subjects in the relative ranges of their level of intake of foods and nutrients and, therefore, it could be useful in epidemiological studies with a diet assessment in the adult population of the Canary Islands.