ObjectiveAdult congenital heart disease patients are prone to health risk behaviors like their peers. Such behaviors can have serious implications, particularly in patients with complex congenital lesions. We investigated patterns in tobacco smoking, alcohol consumption, substance misuse, dental reviews, and physical activity in Maltese patients. DesignA questionnaire modeled on the 2008 European Health Interview Survey was offered to consecutive adult congenital heart disease outpatients, aged 16 years and over, between May 2013 and May 2014. Foreigners and patients with learning difficulties or cognitive impairment were excluded. Data on these habits was compared with that from 372 age-matched and sex-matched 2008 survey responders (general population cohort). ResultsThere were 125 patient responders (65 males; mean age 30.64, SD 12.80 years). Adult congenital heart disease patients smoked less (patients 18.4%, general 32.0% P=.004) and had more regular dental reviews (patients 60.9%, general 45.2% P=.003) but were less physically active than the general population cohort (patients 30.6%, general 62.9% P<.001). The difference in smoking was only significant in patients born after the mid-1970s (younger) and females, while dental reviews were only better in younger and male patients. Male patients consumed alcohol more frequently (38.1%) than general population males (23.3%, P=.02). In the patient cohort, smoking was more likely with milder congenital lesions (OR 4.689, P=.007), substance misuse more likely in males (OR 5.703, P=.036) and with milder lesions (OR 5.405, P=.030) and alcohol consumption more likely in males (OR 11.697, P<.001). ConclusionsAlthough there is an overall lower uptake of some unhealthy habits by Maltese adult congenital heart disease patients, this is not consistent between sexes or age groups. Male and older patients and those with milder lesions might need more reinforcement of the advice given regarding lifestyle habits. All patients need targeted exercise prescription to ensure better physical activity levels.