Introduction and Aims: As medical practitioners of the future, medical students should be taught about tobacco control strategies and smoking cessation interventions. By including education about tobacco in the medical curricula, they can be informed about the health effects of tobacco use and learn to assist smokers to quit. Our study aimed to estimate the extent of teaching about tobacco and smoking cessation techniques in medical schools worldwide and compare with results we reported 10 years ago, to determine the content of curricula and range of teaching formats and to identify barriers to teaching about tobacco in medical schools and solutions. Design and Methods. A cross-sectional survey of all existing medical schools (n = 2090) in 171 countries was conducted. A questionnaire was designed, translated and sent to all medical schools. Main outcome measures included whether and how tobacco is taught; comparisons with the survey conducted 10 years ago; tobacco content in the curriculum; format of teaching; and barriers to teaching and solutions. Results: 665 medical schools from 109 countries completed the full questionnaire, with a response rate of 31.8% from medical schools and 64% of countries and consisting of 39% of medical schools in developed and 28% in less developed countries. A further 67 medical schools responded to a single question on whether they taught about tobacco. The total response rate was 35%. Of 561 medical schools responding to questions on teaching options, 27% of medical schools taught a specific module on tobacco compared with only 11% in our survey of medical schools conducted a decade ago; 77% integrated teaching on tobacco with other topics compared with 40% 10 years ago; 31% taught about tobacco informally as the topic arose (vs. 58%) and 4% did not teach about tobacco (vs. 12%). Most common topics taught were: health effects of smoking (94%), health effects of passive smoking (84.5%), epidemiology of tobacco use (81%), nicotine dependence (78%) and taking a smoking history (75%). Most popular method of teaching was by lectures (78%), case study discussions and problem-based learning exercises (51%), class readings 46%, in the clinical setting with real patients (45%), special projects and assignments (45%) and patient-centred teaching approaches, such as role plays (31%). Significantly, more barriers to teaching were identified by less developed countries (>60%) including: lack of available teaching time in the medical program, limited organisational ability to include new subjects, lack of staff resources to teach, lack of current plans to introduce a tobacco curriculum, lack of a key person to champion and organise teaching, lack of financial resources and lack of incentives or advantages to teach. A majority described solutions to these problems. A case study of education on tobacco throughout the medical curriculum is presented. Discussion and Conclusions.We found an encouraging increase in the extent of teaching on tobacco in medical schools over 10 years.We report that although progress has been made to address the teaching of tobacco in medical schools worldwide, there is a great deal more effort required so that education on tobacco is an ongoing part of medical curricula. The teaching content is generally based on evidence-based smoking cessation guidelines.