Brief interventions are quick, targeted interventions to support individuals to change their health behaviour and reduce future disease risk. Brief interventions are delivered opportunistically in a consultation often initiated for other reasons, and can be as short as 30 seconds. Brief interventions differ from longer and more complex interventions such as health coaching, motivational interviewing, or cognitive behavioural therapies. Brief interventions are effective and cost-effective for smoking cessation, reducing hazardous drinking, weight loss in obesity, and increasing physical activity. Brief interventions typically involve asking about the behaviour, advising on the best way to change it, and assisting by providing or referring to support. Brief interventions can be enhanced by using conversational strategies that avoid stigmatising, create hope and self-efficacy, and facilitate referral or treatment. Brief interventions can be used across a range of health behaviours, such as harmful substance use, using screening tools, and referral to more intensive treatment where necessary. Making Every Contact Count (MECC) is a UK health campaign that aims to use every interaction in healthcare settings to support behaviour change, drawing on motivational interviewing techniques.