The purpose of this study is to increase our understanding of how SMEs retain critical knowledge. Against the background of the underdeveloped body of knowledge regarding knowledge retention, the authors selected an explorative (qualitative) research approach. More precisely, they conducted semi-structured interviews with organization members (i.e. executive and regular staff) of five Austrian SMEs operating in the building and construction industry. This study provides fresh insights into knowledge retention in SMEs. The findings advance the limited understanding of knowledge retention in general and regarding SMEs. They also contribute to the further development of the study of knowledge management in the building and construction sector. Based on the study's findings the authors derive suitable measures to better manage the process of knowledge retention in SMEs. These measures may be useful for SMEs operating in other industries as well.