Background: Non-communicable diseases are a major cause of mortality and morbidity worldwide. They share the same behavioural risk factors (smoking, sedentary behaviour, alcohol consumption and an unhealthy diet), all of which are modifiable risk factors, and biological consequences (hypertension, elevated total cholesterol, obesity and diabetes). Methods: Using data from a series of cross-sectional health examination surveys conducted among the adult population in Finland from 1997 to 2017, a projection of risk factor development (smoking, leisure time sedentary behaviour, hypertension, elevated total cholesterol, overweight and obesity, and diabetes) up to the year 2040 was made. The projections were estimated using a multiple imputation method. Results: Smoking prevalence is estimated to continue to decline up to 2040, similar to hypertension and elevated total cholesterol. By contrast, obesity and diabetes will develop unfavourably, with an increase in prevalence. The increase in obesity is mainly due to polarisation – that is, normal-weight people remain of a normal weight, but overweight people tend to gain more weight and become obese. The observed and estimated changes for leisure time sedentary lifestyle were not statistically significant. Conclusions: Projections of risk factors for non-communicable diseases are needed to guide public health policies and programmes, decision-making and the allocation of health care resources for prevention and care. In Finland, favourable developments have been seen in many of the risk factors, but obesity and diabetes show unfavourable development. There is a need to continue regular, systematic monitoring of the development of risk factors through health examination surveys and to set national goals and programmes to tackle the existing problems.