English: Planning knowledge is increasingly contested while publication pressure on supervisors and their students is mounting. Given these challenges, to what extent has the methodological rigour of South African master’s and doctoral planning theses improved over time? This article examines improvements in methodological rigour of theses completed between 1963 and 2007 by describing how the structure of theses and the use of research designs changed. Data are based on a survey and methodological content analysis of 143 theses sampled by university and programme. Although the structure and ‘science’ of theses improved over time, theses still require better explication of designs, while designs are increasingly limited to case studies and qualitative approaches. It is concluded that a typology of designs for planning research is needed so that students may better choose and explicate their designs.