BackgroundThe number of academic clinicians in the UK is declining and there are demographic inequalities in the clinical-academic workforce. Increased research productivity by medical students is believed to reduce future attrition in the clinical-academic workforce. Thus, this study investigated the association between student demographics and research productivity amongst UK medical students.MethodsThis is a national multicentre cross-sectional study of UK medical students in the 2020/21 academic year. We appointed one student representative per medical school, and they disseminated a 42-item online questionnaire over nine weeks, through departmental emails and social media advertisements. The outcome measures were: (i) publications (yes/no) (ii) number of publications (iii) number of first-authored publications (iv) abstract presentation (yes/no). We utilised multiple logistic and zero-inflated Poisson regression analyses to test for associations between the outcome measures and predictor variables at a 5% significance level.ResultsThere are 41 medical schools in the UK. We received 1573 responses from 36 UK medical schools. We failed to recruit student representatives from three newly formed medical schools, whilst two medical schools prohibited us from sending the survey to their students. Women had lower odds of having a publication (OR: 0.53, 95% CI: 0.33–0.85) and on average had fewer first-author publications than men (IRR: 0.57, 95% CI: 0.37–0.89). Compared to white students, mixed-ethnicity students had greater odds of having a publication (OR: 3.06, 95% CI: 1.67–5.59), an abstract presentation (OR: 2.12, 95% CI: 1.37–3.26), and on average had a greater number of publications (IRR: 1.87, 95% CI: 1.02–3.43). On average, students who attended independent UK secondary schools had a higher rate of first-author publications compared to those that attended state secondary schools (IRR: 1.97, 95% CI: 1.23–3.15).ConclusionOur data suggest that there are gender, ethnic and socioeconomic inequalities in research productivity among UK medical students. To tackle this, and potentially improve diversity in clinical academia, we recommend that medical schools should facilitate targeted high quality research mentorship, funding and training, especially for under-represented-in-medicine students.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12909-023-04412-z.