Sierra Leone has a population of 6.6 million, and around 90% of the labour force in the country works in the informal sector, mostly subsistence or other small-scale agriculture. The extremely low gross domestic product per capita fuels the permanent fiscal deficit of the government, which is aggravated by leakages. The result is that access to health care and education in Sierra Leone is particularly poor. Health care services are often dependent on non-governmental organizations, the goodwill of doctors and nurses, and require unaffordable out-of-pocket payments from the population. In view of this, there is an interest from the government to explore alternatives that would ensure access to health care for the population of Sierra Leone through a social insurance scheme. This study investigates the willingness to pay (WTP) of the informal sector for a health insurance scheme covering a basic health care package, including primary and selected secondary health care services.