In recent years there has been an increasing focus on the physical health of people who suffer from mental illness, it has been recognised that these individuals are at greater risk of physical health problems for a variety of reasons. There are now a number of different guidelines telling us how we should monitor physical health in this population. We searched for randomised trials that looked at the effectiveness of physical health monitoring in preventing deterioration of physical health and maintaining quality of life. Despite the amount of guidance available we found no relevant studies. Consequently there is no evidence from randomised controlled trials that physical health monitoring in people with severe mental illness is useful in preventing deterioration in physical health and maintaining quality of life. This, however, does not mean that physical health monitoring does not affect the physical health of people with severe mental illness.