Activity Theory (AT) is increasingly employed as a lens to guide data analysis in information systems (IS) studies. The theory is also applied to assess and evaluate information systems and technologies (IS/IT) in organisations. Even though its popularity continues to increase in both business and academic domains, there is no formal or assessment guide through which the theory can be applied, which makes it sometimes difficult or complicated. The challenge is significant and critical in that when applied, it influences and shapes the results of the phenomena being studied. This is a problem as results of studies cannot or should not be misconstrued or misrepresented. This study was undertaken to examine how the use of AT in IS studies can be made easy. Based on the findings, a three phase approach was developed and proposed, to guide: (i) the selection of AT in an IS/IT study; (ii) use of elements for data analysis; and (iii) how the elements can be linked with AT components in the analysis of qualitative data. The approach therefore provides a formal guide that can be followed, to ease the selection and application of AT in IS/IT studies as well as assessment of IS/IT artefacts in an organisation. The approach can be useful to researchers for data analysis and interpretation of results. Also, the guidelines can be employed by educators for teaching and learning in the areas of research.