Sufficient knowledge is available about the definition, details and differences of qualitative content and thematic analysis as two approaches of qualitative descriptive research. However, identifying the main features of theme as the data analysis product and the method of its development remain unclear. The purpose of this study was to describe the meaning of theme and offer a method on theme construction that can be used by qualitative content analysis and thematic analysis researchers in line with the underpinning specific approach to data analysis. This methodological paper comprises an analytical overview of qualitative descriptive research products and the meaning of theme. Also, our practical experiences of qualitative analysis supported by relevant published literature informed the generation of a stage like model of theme construction for qualitative content analysis and thematic analysis. This paper comprises: (i) analytical importance of theme, (ii) meaning of theme, (iii) meaning of category, (iv) theme and category in terms of level of content, and (v) theme development. This paper offers a conceptual clarification and a pragmatic step by step method of theme development that has the capacity of assisting nurse researchers understand how theme is developed. As nursing is a pragmatic discipline, nurse researchers have tried to develop practical findings and devise some way to "do something" with findings to enhance the action and impact of nursing. The application of a precise method of theme development for qualitative descriptive data analysis suggested in this paper helps yield meaningful, credible and practical results for nursing.