The ultimate purpose of the study was to find out differences between successful and unsuccessful Finnish SME restructurings. By contrast to previous research, the population of the study was homogeneous, insolvent Finnish small and middle-sized enterprises. In addition to that, a significant sample was achieved with the questionnaire survey which made it possible to generalize the findings. A theoretical sampling plan for the qualitative phase was conducted to build theories of success and failure on SME restructurings in Finland. In order to find out differences between cases, extremes were selected from both success and failure cases in three different size groups of firms: micro firms, small firms and middle-sized firms (six firms in total). Multiple sources of data, both primary and secondary were collected and analysed. Triangulation was conducted to ascertain the validity of findings within and across different research methods. With the help of a multi-method research tool and the approach of the resource-based view of the firm, rich and interesting findings were made. With the findings made by both quantitative and qualitative research methods, a process model of successful restructurings was built. The model includes three basic steps: situation analysis, concentration on the core and the restructuring strategy. These basic factors are affected by six basic forces: reasons for failure, resources of the firm, competitive position of the firm, industry development, stakeholder management, and aspirations of owners and management. The ongoing change management process is in the core of the process model. Numerous other important ingredients that affected the success of restructuring processes were found, for example: the experience of the administrator and the finding that all the problems of the troubled firm must be resolved without delay and the restructuring strategy must be in line with the resources of the troubled firm. The debtrestructurings seemed only to give the troubled firm short-term help. From the creditors' point of view, the going-concern value of the troubled firm should exceed the liquidation value of the firm. Such a position is not going to be achieved without major changes in the business of the troubled firm.