Data sources Medline (1980–present) and bibliographic citations from each article were consulted to find relevant studies. Study selection Analyses were restricted to cohort studies published between 1980 and February 2001 so that any effects of secular trends could be minimised. Studies were included if sample size was over 100 and if the ascertainment of exposure before outcome provided relative risk (RR) and confidence intervals (CI), or enough information to calculate these.Data extraction and synthesis Studies were reviewed by two dentists and two physicians. The RR, CI and standard errors were extracted or calculated. The quality of studies was assessed with a combination of modified Liddle's criteria. Homogeneity was assessed with Q statistics and the data were analysed using a random-effects model. Results The summary RR was 1.19 (95% CI, 1.08–1.32), indicating a higher risk of future cardiovascular events in individuals who had periodontal disease than in those who did not. In an analysis stratified to individuals of ⩽65 years of age, the RR was 1.44 (95% CI, 1.20–1.73).Conclusions Periodontal disease appears to be associated with a 19% increase in the risk of future cardiovascular disease (CVD). This increase in RR is more prominent (44%) in individuals under 65 years of age. The increment of risk between subjects with or without periodontal disease in the general population is modest, at around 20%, because nearly 40% of population has periodontal disease. This modest increase may have a profound public health impact, however.