Dissertation (MSc Information Science)Despite the use of HIS in developing countries, healthcare practitioners rely on manual CDS tools and techniques that cause challenges in their work. However, the use of advanced tools and techniques might make use of the largely accumulated data in order to improve CDS. No studies have explored on the application of data analytics techniques in improving CDS by taking advantage of available clinical data being continuously collected by the existing HIS. The aim of this study was to understand tools and techniques for clinical decision support in developing countries. The study employed qualitative research strategy and adopted an interpretive approach for data analysis. The findings were obtained through the use of case studies conducted in five health facilities in Tanzania. Methods such as key informants’ interviews, artefact examination and document reviews were used in collecting data for the study. Activity theory was used as an interpretive lens through which data were analysed. Besides, during this study development of CDSS prototype was done and demonstrated to healthcare practitioners to obtain their views on the application of data analytics for CDS. This research extends the understanding of tools and techniques for CDS by providing analysis of health practitioners’ clinical decision making practices. This study also contributes to the understanding of the impact of the application data analytics tools and techniques in improving CDSS and resolving the existing challenges identified in this study. The study concludes by suggesting the use of data analytics tools and techniques in improving clinical decision making practices