The present study intends to bring more insights and added value to health systems thinking using systems ideas. It inquires about the current state of health systems thinking, analyses different strengths of alternative systems approaches, and suggests what systems thinking can offer in order to improve the current understanding and the technical performance of health systems. It does not intend to develop a blue print model but rather a more critical approach to deal with some of the intractable problems encountered in current health sector reforms. The thesis is not expected to serve public health practitioners only but also systems thinking theorists, particularly those interested in social systems and pluralism in management sciences. Specifically, this thesis aims at analysing the current state of Health systems thinking; explores what other systems approaches can offer to enlighten health systems; and yields knowledge on critical health systems thinking. To achieve these aims the researcher articulated the study on the basis of the definition of health by the World Health Organisation, the interconnectedness among key health determinants and the global health challenges with particular emphasis in Sub-Saharan Africa. Critical systems thinking is the theoretical framework in which knowledge about systems is expressed and the current state of Health systems thinking is the area of concern in relation to which the researcher has aspirations. The methodology consists in two major steps conducting thought experiments in the context of three scenarios from the researcher's own experience. The first step uses Jackson's four major systems approaches and associated methodologies and yields learning about the current state of health systems thinking; and the second step, using critical systems practice in mode 2, generates a more critical approach to health systems thinking