Objectives This study sought to determine, among a large sample of Australian general practice patients: (1) the prevalence of smoking among different levels of alcohol misuse; and (2) whether the associations between demographic characteristics and alcohol use differ according to smoking status. Methods A cross-sectional survey was administered from 2010 to 2011 to 3559 patients from 12 Australian urban general practices. Patients reported their demographic details, smoking status and their alcohol intake. Results The overall prevalence of reported concurrent smoking and alcohol misuse was 7.8%. Smokers were 3.81-fold more likely to have a higher level of alcohol consumption than non-smokers (95% confidence interval 3.13-4.63; P<0.0001). There was evidence that smoking was an effect modifier of the relationship between alcohol misuse and chronic illness. Conclusions There was an increasing prevalence of smoking with increasing level of alcohol consumption. In addition, those with chronic conditions who smoked had greater odds of higher levels of alcohol consumption. Preventative interventions for these substances are needed to reduce the burden associated with concurrent smoking and alcohol misuse. What is known about the topic? Tobacco and alcohol are the most commonly used substances and contribute to over 10million deaths annually. The risk of disease is high when using either of these substances, however, concurrent use is associated with a greatly compounded risk. Australian data is limited regarding the prevalence of concurrent tobacco and alcohol misuse, however, international studies suggest variation in prevalence rates between different clinical settings. What does this paper add? This study examined the prevalence of concurrent smoking and alcohol misuse among different levels of alcohol misuse severity within an Australian general practice setting. Additionally it explored whether the associations between demographic characteristics and alcohol use differ according to smoking status. What are the implications for practitioners? This study has important implications for disease prevention and the delivery of preventive health services by general practitioners. Considering one in 100 clinical treatments provided in general practice relate to preventative smoking or alcohol counselling, it is critical that efforts are made to ascertain risk factors such as smoking and alcohol misuse to increase treatment rates. General practitioners should consider screening for smoking and alcohol misuse opportunistically during routine clinical encounters, as well as screening for smoking or alcohol misuse if one or the other is present.