This article undertakes the issue of development assistance, which is one of the factors shaping human security. It is a human right, which refers to the security of people and communities, as opposed to the security of states. Also, human security recognises several dimensions related to feeling safe, such as freedom from fear, freedom from want and freedom from indignity. This people-centred approach to security has implications on how we carry out and understand development cooperation. The aim of the article is to analyse the effectiveness of development policy and development cooperation conducted by Sweden in 2000-2018 in the light of the principles of the English School of International Relations. The English School of IR is referred to as liberal realism. It maintains that there is a “society of states” at the international level, despite the condition of anarchy. The English School stands for the conviction that ideas, rather than simply material capabilities, shape the conduct of international politics, and therefore they deserve analysis and critique. The article discusses the assumptions of development assistance in the light of the English School’s guidelines. The organisation and management of development assistance in Sweden were characterised in the article. The last part examines the effectiveness of the development assistance provided by analysing selective cases and the Human Development Index (HDI). The focus of the article should be drawn to the fact that a human being is placed in the very centre of the Swedish projects. The donors’ attention focuses exactly on people. Similarly, in the case of the concept of human security and sustainable development, Sweden’s aid policy serves as an example of actions, which are a model for other states and may be used for reference purposes by them.