This paper explores some current issues for certifying medical practitioners in the United Kingdom (UK), particularly general practitioners (GPs), who provide medical advice to their patients on fitness for work. Medical statements that doctors use to record this advice, such as form Med 3 and form Med 4, may be used by patients as evidence to support claims for financial benefits, including Statutory Sick Pay (SSP) and state incapacity benefits. The UK employment context for sick or disabled people of working age is beginning to change, but many barriers to work retention and work resumption still exist. The UK government has embarked on a wide range of reforms that are aimed at improving work opportunities for disabled people. Research evidence on certification practice, coupled with a better understanding of the factors that can create and perpetuate sickness absence from work, suggest possible areas for reviewing clinical practice. An agenda for improving the quality of advice provided to patients of working age in the primary health care setting will need to encompass visible professional leadership, more research into current practice, and an adequately resourced programme of education for all key stakeholders.