Medical students founded WEMOS in 1979 as a working group on health care and development cooperation. The main objective of WEMOS is to improve the health of men, women and children in developing countries by influencing international policy. WEMOS believes that international standards, legislation and agreements are necessary in protecting and promoting people's health in developing countries.

WEMOS follows five distinct strategies: lobbying, information gathering, cooperation with partners in the developing countries, cooperation with other organisations, and campaigning among Dutch healthcare professionals.

People in developing countries have a right to good health. Through its projects, WEMOS wants to contribute to the fulfilment of that right. The organisation focuses on three specific areas: 1) Health and Trade: to promote better healthcare and access to healthcare services within trade policies; 2) Health and Poverty: to develop and lobby for strategies for poverty reduction and debt reduction/cancellation for Southern countries; 3) Health and the role of the private sector: to ensure that global public-private initiatives make a real contribution in terms of improving the health situation in developing countries.