Background: Influenza infections are frequently implicatedin the exacerbation of asthma. The aim of this study was toassess vaccination coverage among Spanish children andadults with asthma and to describe the factors associated(predictors) with vaccination, using data from the 2006Spanish National Health Survey. Patients and Methods: Subjects were classified as asthmasufferers if they answered affirmatively to the question, "Hasyour doctor told you that you (or your child) currently sufferfrom asthma?" Influenza vaccination status was assessed viathe question, "Did you (or your child) have a flu shot in thelatest campaign?" The following were analyzed as possiblepredictors of influenza vaccination: sociodemographic variables;health-related and lifestyle variables; variables linkedto the use of healthcare services. Results: A total of 38,329 records of individuals aged over6 months were analyzed, and of these, 2,337 were classifiedas asthmatics. Among asthmatics, overall influenza coveragewas 32.6% (18.8% among children, and 38% among adults).Whereas the sole variable that predicted a higher coverageamong children was parents' negative perception of theirchild's health, among adults positive predictors includedolder age, lower educational level, suffering from concomitantchronic disease, and non- or ex-smoker status. Conclusions: The overall influenza vaccination coverageamong subjects who suffer from asthma in Spain is verylow. Special attention should be paid to children, youngeradults, and smokers, since these subjects have the lowestadherence to vaccine recommendations. Strategies focusedon health-care providers and patients must be urgentlyimplemented to improve influenza vaccination coverageamong asthma sufferers.