Using this dataset we assessed whether mental health labels presenting information of the benefits of quitting smoking for mental health was more effective than blank labels and physical health labels, and if there were any differences between those with mental ill health, or not. Participants took part in an online randomised experiment, with three conditions: i) mental health labels; ii) physical health labels; iii) blank labels. Participants were randomly allocated to label condition, stratified by mental health status, and viewed four labels for at least 10 seconds each. Motivation to stop smoking was measured using the Motivation to Stop Scale (MTSS) before and after viewing the labels.